JP4247978B2 - Rotating anode type X-ray tube device - Google Patents

Description

  The present invention relates to a rotary anode X-ray tube and a method for manufacturing the same, and more particularly to a rotary anode X-ray tube using a hydrodynamic slide bearing using a liquid metal lubricant, and a liquid metal even under adverse conditions. The present invention relates to a rotation mechanism that can prevent leakage of a lubricant and, for this reason, can simplify the manufacturing process of a rotary anode X-ray tube and improve reliability.

  As is well known, a rotary anode type X-ray tube supports a disk-shaped X-ray target rotatably by a rotating body and a fixed body having a bearing portion, and energizes an electromagnetic coil of a stator disposed outside a vacuum vessel. Then, while rotating the X-ray target at a high speed, the X-ray target surface is irradiated with electrons emitted from the cathode and accelerated to emit X-rays. The bearing portion is a rolling bearing such as a ball bearing, or a helical groove formed on the bearing surface and a liquid metal lubricant such as gallium (Ga) or gallium-indium-tin (Ga-In-Sn) alloy. It is constructed using a hydrodynamic slide bearing filled in the gap. Examples of using the latter sliding bearing are, for example, JP-B-60-21463, JP-A-60-97536, JP-A-62-287555, JP-A-2-227947, USP5068885, JP-A-2-244545. US Pat. No. 5,077,776, JP-A-2-227948, JP-A-5-13028, or JP-A-2001-325908.

  A rotating anode type X-ray tube having a hydrodynamic slide bearing using a liquid metal lubricant has a rotating body rotating at a high speed of about 3000 rpm to 9000 rpm during operation, and the rotation axis changes in an unspecified direction. There are many. At that time, no matter what direction the tube axis of the rotary anode X-ray tube is, the liquid metal lubricant is always supplied to the hydrodynamic slide bearing portion having the spiral groove without excess or deficiency. Need to be prevented from leaking into the vacuum space.

  In a conventionally known rotary anode type X-ray tube, as disclosed in, for example, Japanese Patent Laid-Open No. 5-13028, a storage chamber for a liquid metal lubricant is formed by an elongated hole formed in the center of a columnar fixed body. There is an example in which the liquid metal lubricant is supplied to the hydrodynamic slide bearing through a lubricant passage that is configured and radially extends from the storage chamber of the liquid metal lubricant toward the bearing portion. In this configuration, the length of the lubricant passage from the lubricant storage chamber to the bearing portion is undesirably increased, and depending on the position of the rotary anode X-ray tube, the supply of the liquid metal lubricant to a specific portion of the slide bearing is prevented. There are cases where it is difficult to carry out, and there is a problem that the gas that has come out inside is difficult to exhaust.

  In this rotating mechanism structure, the lubricant storage chamber is provided inside the fixed body, and each dynamic pressure type slide bearing does not communicate directly with the vacuum space. In the case of expansion due to temperature, the liquid metal lubricant may be ejected when the rotating body is closed by being closed by the internal liquid metal lubricant and becoming a high pressure. In order to avoid this, it was necessary to assemble the rotating mechanism with a special treatment. For example, in Japanese Patent Laid-Open No. 6-176720, it is necessary to assemble a rotating mechanism in a vacuum environment, and the filling amount of the liquid metal lubricant is the end of the spiral groove sliding bearing portion closest to the space inside the vacuum vessel. Therefore, it is disclosed that the upper limit of 70% of the internal space in which the liquid metal lubricant on the other bearing side can flow is disclosed. This indicates that it is necessary to enlarge the space allowing the internal gas to expand because the gas passage is closed by the spiral groove sliding bearing portion closest to the space inside the vacuum vessel.

  Other measures have been made to prevent the liquid metal lubricant from leaking into the internal space of the vacuum vessel. For example, in Japanese Patent Laid-Open No. 4-363845, a cavity having a large volume is provided in the vicinity of the end where the slide bearing portion communicates with the internal space of the vacuum vessel, and the gas contained in the liquid metal lubricant is separated in this space. In addition, it is disclosed that a lubricant leakage preventing means for suppressing the passage of the liquid metal lubricant is provided on the way from the cavity to the internal space of the vacuum vessel. Further, it is also disclosed that the lubricant leakage preventing means has a surface material that does not get wet with the liquid metal lubricant, and has a pump spiral groove formed on the inner peripheral wall of the rotating body. Has been. The reason why these devices are required is that the slide bearing provided at a position closest to the path leading to the internal space of the vacuum vessel is a hydrodynamic slide bearing that substantially supports the rotating body. Further, these devices are irreversible with respect to leakage of the liquid metal lubricant because the liquid metal lubricant is performed only in a portion closer to the vacuum space than the hydrodynamic slide bearing.

  Other measures have been made to prevent the liquid metal lubricant from leaking into the internal space of the vacuum vessel. For example, in JP-A-4-144046, a small diameter portion of a fixed body is provided in the vicinity of an opening of a rotating body, and a liquid metal lubricant is slid between the small diameter portion and an opening closing body surrounding the small diameter portion. An example in which a pump that pushes in the direction of the bearing portion is configured is disclosed. Japanese Patent Laid-Open No. 2002-245958 also describes a similar rotating mechanism. However, in these devices, the movement of the liquid metal lubricant and the gas flow are performed by the slide bearing provided in the position closest to the path leading to the internal space of the vacuum vessel and the liquid metal lubricant in the lubricant passage provided radially. Since the movement is restricted, if a large amount of gas is contained inside the rotating mechanism, the inside of the rotating mechanism becomes a high pressure due to the expansion of this gas, and this high pressure causes a higher pressure than the outermost slide bearing. A large amount of liquid metal lubricant may be extruded on the outside. When the volume of the liquid metal lubricant reaches a certain value or more, the liquid metal lubricant in excess is pushed out of the opening blockage. Furthermore, when the radial passage provided outside the outermost slide bearing as described in JP-A-4-144046 is designed to pass only gas, the outermost The liquid metal lubricant once pushed out of the slide bearing cannot return to the original slide bearing in the rotation mechanism, and the rotation mechanism as a whole only forms an irreversible passage for the liquid metal lubricant. . The same applies to the case where there is no passage leading to the inside of the rotation mechanism outside the outermost slide bearing as in the example described in JP-A-2002-245958. On the contrary, when the radial passage provided outside the outermost slide bearing as described in JP-A-4-144046 passes through the liquid metal lubricant. A large amount of liquid metal lubricant may leak from this passage. In any case, these devices are effective only when the inside of the rotation mechanism is maintained at a high vacuum, and it is considered that the special process and special equipment as described above are necessary at the time of manufacture.

  Even if such a device is devised, the liquid metal lubricant may leak into the internal space of the vacuum vessel, and other efforts have been made to prevent this. For example, in Japanese Patent Laid-Open No. 5-13029, a jacket is attached to at least one of a rotating body and a fixed body so as to surround an opening that leads from a sliding bearing portion to an inner space of a vacuum vessel, and a cavity is formed inside the jacket. Examples have been disclosed. Similarly, Japanese Patent Application Laid-Open No. 6-325706 discloses that a surface of a spatial passage that connects a hydrodynamic slide bearing gap and an inner space of a vacuum vessel is a surface that is not wetted by a liquid metal lubricant, and a surface that is not wetted by this lubricant. An example is disclosed in which at least one trap cavity for supplementing a lubricant leaking through the passage is provided in the middle of the spatial passage constituted by: In these examples, the liquid metal that has come out of the opening that leads from the sliding bearing portion to the inner space of the vacuum vessel is confined in the cavity in the jacket or the trap cavity, and the liquid metal lubricant reaches the inner space of the vacuum vessel. Hope not to.

  Japanese Patent Laid-Open No. 2-244545 discloses that a surface on which an opening region for communicating a bearing with a vacuum region is formed contains a gold or other noble metal substance and is wetted by a liquid metal lubricant. It is disclosed that the liquid metal lubricant leaking from the opening region is adhered so as not to reach the vacuum region. Further, in US Pat. No. 5,654,999, at least one annular groove is provided in an inner portion of a rotor provided separately from a liquid metal flat bearing, and this groove is used to apply liquid metal lubricant to centrifugal force during rotation of the rotor. Discloses an example in which a liquid metal lubricant flows from the bearing gap into the annular groove of the rotor and is held therein. These are all devices for preventing the liquid metal lubricant that has come out of the bearing portion from reaching the vacuum space. These are not safe because the part where the liquid metal lubricant is expected to be held leads directly to the vacuum space.

  Even with the above-described devices, it is necessary to minimize leakage of the liquid metal lubricant that leaks from the bearing portion to the path leading to the vacuum space. A process was required. For example, Japanese Patent Laid-Open No. 5-290734 discloses a posture in which at least a part of a gap from the sliding bearing portion to the internal space of the vacuum vessel is above the waterline of the liquid metal lubricant in a state where the rotating body is not rotated. It is disclosed that it is necessary to include an exhausting step. Japanese Patent Application Laid-Open No. 8-111194 and Japanese Patent Application Laid-Open No. 2002-245958 require a step of exhausting the tube axis of the rotary anode X-ray tube in the vertical direction, and an exhaust in the horizontal direction. There is a disclosure to the effect. Further, US Pat. No. 5,668,849 also discloses that it is necessary to repeat such a change in posture during the manufacturing process. In order to realize this, an exhaust equipment capable of changing the attitude of the rotary anode type X-ray tube during the exhaust process is required, and the equipment cost becomes expensive.

As described above, the main reason why the manufacturing process of the rotary anode X-ray tube had to be specially limited is that the liquid metal lubricant leaked from the bearing portion reaches the vacuum space. This is considered to be because it was not to obtain a solution to the leakage from the bearing part itself.
Japanese Patent Publication No. 60-21463 JP-A-60-97536 JP-A-62-287555 JP-A-2-227947 JP-A-2-244545 JP-A-2-227948 Japanese Patent Laid-Open No. 4-144046 JP-A-4-363845 Japanese Patent Laid-Open No. 5-12997 Japanese Patent Laid-Open No. 5-13028 Japanese Patent Laid-Open No. 5-13029 Japanese Patent Laid-Open No. 5-290734 Japanese Patent Application Laid-Open No. 5-290771 Japanese Patent Laid-Open No. 6-13007 JP-A-6-176720 JP-A-6-325706 Japanese Patent Laid-Open No. 8-111194 Japanese Patent Laid-Open No. 9-35633 JP-A-11-213927 JP 2001-189143 A JP 2001-325908 A JP 2002-184334 A JP 2002-245958 A USP 5068885 US Pat. No. 5,077,775 USP 5077776 US Pat. No. 5,189,688 US Pat. No. 5,195,119 US Pat. No. 5,298,293 US Pat. No. 5,384,819 US Pat. No. 5,583,907 US Pat. No. 5,654,999 US Pat. No. 5,668,849 USP 6477232B2 publication USP 6477236B1 USP 6546078 B2 publication

  A problem to be solved is a rotating mechanism having a structure in which a liquid metal lubricant is not leaked when exhausting even if a gas is contained in a bearing portion in a rotary anode type X-ray tube using a slide bearing using a liquid metal as a lubricant. In manufacturing this rotary anode X-ray tube, it can be easily and quickly made stable without the need for additional processes or special equipment in the assembly process or exhaust process of the rotary anode X-ray tube. It is an object of the present invention to provide a rotary anode X-ray tube and a rotary anode X-ray tube apparatus which can be manufactured in an improved manner and improved so that the reliability of the manufactured rotary anode X-ray tube can be increased.

  The present invention substantially supports a rotating body in a direction along a rotation axis and a direction perpendicular to the rotation axis in a rotation mechanism of a rotary anode X-ray tube using a slide bearing using a liquid metal as a lubricant. In addition to the sliding bearings, a liquid metal lubricant is supplied to these sliding bearings, and an auxiliary sliding bearing for preventing the liquid metal lubricant from leaving the bearing portion is provided. This auxiliary sliding bearing ensures a bearing gap of a certain size or larger under any circumstances, and usually has a gap not filled with the liquid metal lubricant, and the liquid metal lubricant is retained only in a part. I'm leaning. The amount of the liquid metal lubricant in the auxiliary sliding bearing increases or decreases depending on the operating conditions, and when the pressure to push out the liquid metal lubricant increases when the rotating body rotates. The amount of liquid metal lubricant is increased to produce a pressure in the opposite direction that is large enough to counter this pressure. When the rotating body is stationary, the amount of liquid metal lubricant in the auxiliary slide bearing is small, and the movement is easy, and the gas contained in the liquid metal lubricant does not increase in pressure. It can be exhausted outside.

  First, the device of the sliding bearing structure will be described. An annular reservoir is provided on both sides of the hydrodynamic slide bearing that uses liquid metal as a lubricant. The annular reservoir communicates with the entire circumference of the slide bearing so that each annular reservoir does not pass through the slide bearing and does not include a portion that is bent in the radial direction. Are connected by a large number of lubricant passages provided as described above, and have a function of a large number of independent closed circulation paths. The annular reservoir is surrounded by an annular deep groove that is deeply cut in the radial direction from the surface of the fixed body, and the surface of the rotating body that is opposed to the surface of the fixed body with a minute gap. It consists of being supplied. The annular reservoir in the present invention includes a space that is not occupied by the liquid metal lubricant, and the liquid metal lubricant and gas can be easily replaced. It is not limited to the so-called reservoir concept conventionally used in the field. The closed circuit described above serves to facilitate the supply of the liquid metal lubricant to the slide bearing around the entire circumference and to separate the gas contained in the liquid metal lubricant in the closed circuit. The annular reservoir and the lubricant passage have a sufficiently large cross section, and the capillary effect in this is negligible, and the movement of the liquid metal lubricant and the replacement with gas can be easily performed. . In the rotating mechanism including the annular reservoir and the lubricant passage, a space not filled with the liquid metal lubricant is provided, and the movement of gas in this portion is not obstructed. When the rotating body is stationary in a horizontal position, even if gas is generated somewhere, if the pressure of this gas increases to some extent, this gas pushes some liquid metal lubricant or liquid metal lubrication. It is replaced with an agent and reaches the annular reservoir, and this gas floats upward. At this time, there is no structure for preventing the gas from floating in the annular reservoir, and such a space formed above the rotating mechanism can be distributed by cutting the rotating mechanism vertically. ing.

In the bearing structure as described above, gas can be easily separated at the bearing portion. However, since an annular reservoir containing a large amount of liquid metal lubricant is provided at a position near the end opening, the liquid from here It is necessary to prevent leakage of the metal lubricant. This is achieved as follows. The end of the rotating body has an end opening leading to a vacuum space. An annular forbidden band for preventing the passage of the liquid metal lubricant by surface tension is provided on the side closer to the end opening than the annular reservoir located closest to the end opening. An auxiliary sliding bearing is provided further on the side facing the end opening than the annular forbidden band. The annular forbidden band is formed of a pair of surfaces that are opposed to each other with a minute gap between the rotating body and the fixed body and are not wetted with the liquid metal lubricant. The auxiliary sliding bearing is opposed to the rotating body and the stationary body with a minute gap therebetween and wetted with a liquid metal lubricant, and a spiral groove provided on at least one surface, It consists of a liquid metal lubricant present in this. The liquid metal lubricant is normally separated from the liquid metal lubricant in other parts including the annular reservoir by the annular forbidden band. When the pressure in the space in the rotating mechanism is increased to some extent when the rotating body is stationary, the separated liquid metal lubricant is pushed outward, and at this time, a part of the ring of the liquid metal lubricant is The gas passage which cut | disconnects and connects the said space and external space arises temporarily, and gas is discharged | emitted outside. In this case, the liquid metal lubricant located in an auxiliary sliding the bearing will not protrude to the outside of the bearing because the amount is small.

  If the liquid metal lubricant moves to a path leading to the vacuum space rather than the auxiliary slide bearing for an unexpected reason, the liquid metal lubricant is returned to the auxiliary slide bearing by the feedback means. ing. If the liquid metal lubricant in the auxiliary sliding bearing increases, it is returned to the annular reservoir via the annular forbidden band. Further, the liquid metal lubricant that has further advanced the path leading to the vacuum space without being returned for an unexpected reason is confined in a closed space provided in the rotating body. Since the device described above has been devised, even if gas is contained in the rotating mechanism or in the liquid metal lubricant, no special consideration is required regarding leakage of the liquid metal lubricant, and the gas can be easily exhausted, so that The problem has been solved. More specific problem-solving means employed in the present invention are as follows.

One aspect of the present invention is a vacuum container that defines a vacuum space, and a substantially cylindrical shape that is mechanically supported by a part of the vacuum container and protrudes into or penetrates the vacuum container. a fixed body having a central axis in the rotating body X-ray target and a portion comprising a coaxially fitted to the substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body is mounted coaxially And a rotary anode type X-ray tube comprising a spiral groove provided in a fitting portion between the fixed body and the rotating body and a hydrodynamic slide bearing having a liquid metal lubricant filled therein. There is an end opening that is an annular gap communicating with the vacuum space at a position where the surface of the body and the surface of the terminal end of the rotating body face each other, and the hydrodynamic slide bearing has a direction along the central axis. A pair of thrust bearings producing pressure And three radial bearings that generate pressure in a direction perpendicular to the central axis, and these three radial bearings include auxiliary radial bearings. A surface portion provided with a spiral groove for a radial bearing and a surface portion facing this surface portion with a gap therebetween, and the liquid metal lubricant normally occupies the gap between these surface portions. There is a region and a region not normally occupied by the liquid metal lubricant, and the volume ratio of these regions is a rotating anode type X-ray tube characterized by being not constant over time. In this rotary anode type X-ray tube, the rotating body is substantially pivotally supported by the pair of thrust bearings and two radial bearings excluding the auxiliary radial bearing, and the rotational characteristics are substantially These hydrodynamic slide bearings are determined, and the auxiliary radial bearing has substantially no influence on the rotational characteristics, and supplies liquid metal lubricant to other hydrodynamic slide bearings, and the internal structure of the rotary mechanism. This prevents the liquid metal lubricant from leaking out of the rotary mechanism toward the outside. In the auxiliary radial bearing, a portion not usually filled with the liquid metal lubricant occupies a large proportion, and the generated pressure is usually not large. When the liquid metal lubricant is pushed into the auxiliary radial bearing while the rotating body is rotating, a spiral groove is provided in a direction to generate a pressure against the pushing pressure. When the liquid metal lubricant enters the pressure, the pressure in the opposite direction is balanced and the boundary of the liquid metal lubricant no longer moves. In this way, the liquid metal lubricant is prevented from being extruded. When the rotating body is stationary, the space that is not occupied by the liquid metal lubricant occupies a large proportion in the auxiliary radial bearing. Therefore, even if the liquid metal lubricant is moved by expansion of the gas inside the rotor, etc. Before being pushed out from the region where the spiral groove of the auxiliary radial bearing is provided, it is broken by itself to form a gas passage, and the gas is exhausted. In this way, the auxiliary radial bearing automatically optimizes the distribution of the liquid metal lubricant.

One aspect of the present invention is a vacuum container that defines a vacuum space, and a substantially cylindrical shape that is mechanically supported by a part of the vacuum container and protrudes into or penetrates the vacuum container. a fixed body having a central axis in the rotating body X-ray target and a portion comprising a coaxially fitted to the substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body is mounted coaxially And a rotary anode type X-ray tube comprising a spiral groove provided in a fitting portion between the fixed body and the rotating body and a hydrodynamic slide bearing having a liquid metal lubricant filled therein. There is an end opening that is an annular gap communicating with the vacuum space at a position where the surface of the body and the surface of the terminal end of the rotating body face each other, and the hydrodynamic slide bearing has a direction along the central axis. 3 thrust bearings producing pressure And two radial bearings that generate pressure in a direction perpendicular to the central axis, and these three thrust bearings include auxiliary thrust bearings. And a surface portion provided with a spiral groove for a thrust bearing and a surface portion facing this surface portion with a gap therebetween, and the liquid metal lubricant normally occupies the gap between these surface portions. There is a region and a region not normally occupied by the liquid metal lubricant, and the volume ratio of these regions is a rotating anode type X-ray tube characterized by being not constant over time. In this rotary anode type X-ray tube, the rotating body is substantially pivotally supported by the two radial bearings and the two thrust bearings excluding the auxiliary thrust bearing, and the rotational characteristics are substantially the same. These auxiliary hydrodynamic bearings are substantially unaffected by rotational characteristics, and supply of liquid metal lubricant to other hydrodynamic slide bearings and rotation mechanism It plays the role of preventing the liquid metal lubricant from leaking from the inside toward the outside of the rotating mechanism. In the auxiliary thrust bearing, a portion not usually filled with the liquid metal lubricant occupies a large proportion, and the generated pressure is usually not large. When the liquid metal lubricant is pushed into the auxiliary thrust bearing while the rotating body is rotating, a spiral groove is provided in a direction that generates a pressure that opposes the pushing pressure. When the liquid metal lubricant enters the pressure, the pressure in the opposite direction is balanced and the boundary of the liquid metal lubricant no longer moves. In this way, the liquid metal lubricant is prevented from being extruded. When the rotating body is stationary, the space that the liquid metal lubricant does not occupy in the auxiliary thrust bearing occupies a large proportion, so even if the liquid metal lubricant is moved due to expansion of the internal gas, etc. Before being pushed out from the region in which the spiral groove of the auxiliary thrust bearing is provided, it is broken by itself to form a gas passage, and the gas is exhausted. In this way, the auxiliary thrust bearing automatically optimizes the distribution of the liquid metal lubricant.

  One of the present invention is one of the auxiliary radial bearing or the auxiliary thrust bearing, and any of these auxiliary bearings and other hydrodynamic slide bearings that substantially support the rotating body. At a position sandwiched in the direction along the central axis by the heel, the surface portion of the fixed body and the surface portion of the rotating body facing the surface with a minute gap are wetted with a liquid metal lubricant. A rotating anode type X-ray tube according to any one of the above inventions, wherein an annular forbidden band comprising an annular surface portion is formed. In this rotary anode type X-ray tube, the annular forbidden band is provided between the auxiliary radial bearing or the hydrodynamic slide bearing adjacent to the auxiliary thrust bearing and substantially supporting the rotating body. Since there is no excessive pressure applied to the liquid metal lubricant, a hydrodynamic slide bearing that substantially supports the rotating body and the auxiliary radial bearing or the auxiliary thrust bearing And the auxiliary radial bearing or the auxiliary thrust bearing operates independently. Therefore, when the rotating body is stationary, the amount of the liquid metal lubricant that normally exists in the auxiliary radial bearing or the auxiliary thrust bearing can be easily limited.

One of the present invention is a portion of the fixed body at a position sandwiched in a direction along the central axis between any one of the hydrodynamic slide bearings that substantially support the rotating body and the annular forbidden band, annular deep groove said annular bandgap having a depth of greater dimension than the opening width of the opening and the opening having an opening width of a dimension greater than the gap dimension between the surfaces facing each other constituting the annular bandgap A rotary anode type X-ray tube according to any one of the above inventions, characterized in that the rotary anode type X-ray tube is provided adjacent to the rotary anode type X-ray tube. In this rotary anode type X-ray tube, the annular deep groove supplies liquid metal lubricant into a hydrodynamic slide bearing that substantially supports the rotating body and separates gas mixed in the liquid metal lubricant. It is useful for. There is a space not filled with the liquid metal lubricant in the annular deep groove, and when gas accumulates in this portion, the gas passes through the annular forbidden band and passes through the auxiliary radial bearing or the auxiliary thrust bearing. A wall made of a small amount of liquid metal lubricant accumulated inside is broken, and this gas is exhausted to the outside. As described above, the annular deep groove constitutes an annular reservoir, and is connected to another annular reservoir inside the rotation mechanism by the plurality of lubricant passages, and the auxiliary radial bearing or the auxiliary reservoir. The liquid metal lubricant that has passed through the annular forbidden band from the thrust bearing and returned to the annular deep groove is in any of the hydrodynamic slide bearings that substantially support the rotating body inside the rotating mechanism. It can be reached. In other words, a reversible passage of the liquid metal lubricant is formed which extends from the auxiliary radial bearing or the auxiliary thrust bearing to any of the hydrodynamic slide bearings that substantially support the rotating body. It will be.

One of the present invention, a gap in the surface portion and the surface portion of the auxiliary for the radial bearing or the auxiliary in the fixed body in a region where the spiral grooves are provided for the thrust bearing face in the positive displacement of the surface portion and the gap portion sandwiched can be in the rotating body, the surface portion of the rotating body which faces have the fixed body surface portion with a gap thereto constituting the annular bandgap The rotary anode X-ray tube according to any one of the above inventions, wherein the volume is larger than a volume of a gap portion formed by being sandwiched. In this rotary anode type X-ray tube, pressure is applied to the liquid metal lubricant from both sides of the annular forbidden band, and the pressure applied to the liquid metal lubricant is reduced after the annular forbidden band is filled with the liquid metal lubricant. Thus, even if all of the liquid metal lubricant therein moves into the auxiliary radial bearing or the auxiliary thrust bearing, the liquid metal lubricant does not protrude from the auxiliary bearing, and the liquid metal lubricant leaks out. Can be reliably prevented.

  One aspect of the present invention is that the area of the surface portion of the fixed body or the rotating body in the region where the spiral groove for the auxiliary radial bearing or the auxiliary thrust bearing is provided is the annular forbidden band. The rotary anode X-ray tube according to any one of the above-mentioned inventions, wherein the area is larger than the area of the surface portion of the fixed body constituting the structure. In this rotary anode type X-ray tube, pressure is applied to the liquid metal lubricant from both sides of the annular forbidden band, and the pressure applied to the liquid metal lubricant is reduced after the annular forbidden band is filled with the liquid metal lubricant. Thus, even if all of the liquid metal lubricant therein moves into the auxiliary radial bearing or the auxiliary thrust bearing, it is easy to prevent the liquid metal lubricant from protruding from these auxiliary bearings. For example, even if the gap between the surface of the rotating body and the surface of the fixed body is substantially the same, leakage of the liquid metal lubricant can be prevented as described above.

  One aspect of the present invention is that the diameter of the surface portion of the fixed body constituting the auxiliary radial bearing or the auxiliary thrust bearing is substantially equal to the diameter of the surface portion of the fixed body constituting the annular forbidden band. The rotary anode X-ray tube according to any one of the above inventions, characterized in that This rotary anode type X-ray tube has a simple structure and can easily prevent leakage of the liquid metal lubricant as described above.

One aspect of the present invention is a vacuum container that defines a vacuum space, and a substantially cylindrical shape that is mechanically supported by a part of the vacuum container and protrudes into or penetrates the vacuum container. a fixed body having a central axis in the rotating body X-ray target and a portion comprising a coaxially fitted to the substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body is mounted coaxially And a rotary anode type X-ray tube comprising a spiral groove provided in a fitting portion between the fixed body and the rotating body and a hydrodynamic slide bearing having a liquid metal lubricant filled therein. There is an end opening that is an annular gap communicating with the vacuum space at a position where the surface of the body and the surface of the terminal end of the rotating body face each other, and the hydrodynamic slide bearing has a direction along the central axis. One that substantially supports the rotating body. And a first radial bearing and a second radial bearing that substantially support the rotating body in a direction perpendicular to the central axis, and an auxiliary third radial bearing. The third radial bearing is disposed at a position closest to the end opening, and the liquid metal lubricant that has moved to a position closer to the end opening than the third radial bearing is contained in the third radial bearing. The rotary anode type X-ray tube is characterized in that a feedback means for returning using centrifugal force is provided. In this rotary anode type X-ray tube, even if the liquid metal lubricant moves to a position closer to the end opening than the third radial bearing due to an unexpected cause, the feedback means causes the inside of the third radial bearing. Thus, since the liquid metal lubricant does not reach the vacuum space, it is possible to prevent inconvenience such as discharge.

In one aspect of the present invention, the outer surface portion of the fixed body and the inner surface portion of the rotating body facing the outer surface portion of the fixed body at a position closer to the end opening than the third radial bearing are maintained. A small diameter portion having a diameter smaller than the diameter of the surface portion of the third radial bearing is provided, and the feedback means includes an inner surface portion of the small diameter portion of the rotating body and the third radial bearing. it is a rotating anode X-ray tube according to the invention above, characterized in that it includes a return hole that liquid metal lubricant is open to the vicinity of the bearing clearance can pass. In this rotary anode X-ray tube, the feedback means is realized with a simple structure.

  One aspect of the present invention is that liquid metal lubrication is performed on at least one of the outer surface portion of the small-diameter portion of the fixed body and the inner surface portion of the small-diameter inner portion of the rotating body toward the opening of the return hole. A rotary anode X-ray tube according to any one of the above inventions, characterized in that introduction means for introducing the agent is provided. In this rotary anode type X-ray tube, when the liquid metal lubricant moves to a position closer to the end opening than the third radial bearing, the liquid metal lubricant is introduced into the opening of the return hole by the introducing means. The liquid metal lubricant is efficiently returned to the third radial bearing.

  In one aspect of the present invention, the return hole has an inner surface that is not wetted by the liquid metal lubricant, and when the rotating body is stationary, the liquid metal lubricant passes through this surface tension. When the rotating body is rotating, it is a one-way passage that moves the liquid metal lubricant from the small inner diameter portion toward the bearing gap of the third radial bearing by centrifugal force. A rotating anode X-ray tube according to any one of the above inventions. In this rotary anode type X-ray tube, the liquid metal lubricant is prevented from leaking back through the return hole.

  In one aspect of the present invention, the return holes are opened at respective positions distributed along the central axis direction or the circumferential direction of the small inner diameter portion of the rotating body, or along both directions thereof, and A rotating anode X-ray tube according to any one of the above inventions, comprising a plurality of holes arranged around a central axis. In this rotary anode X-ray tube, the return path can be realized with a simple structure.

One aspect of the present invention is a vacuum container that defines a vacuum space, and a substantially cylindrical shape that is mechanically supported by a part of the vacuum container and protrudes into or penetrates the vacuum container. a fixed body having a central axis in the rotating body X-ray target and a portion comprising a coaxially fitted to the substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body is mounted coaxially And a rotary anode type X-ray tube comprising a spiral groove provided in a fitting portion between the fixed body and the rotating body and a hydrodynamic slide bearing having a liquid metal lubricant filled therein. There is an end opening that is an annular gap communicating with the vacuum space at a position where the surface of the body and the surface of the terminal end of the rotating body face each other, and the rotating body is a first to which the X-ray target is attached. The rotating body member and the gap A second rotating body member that is coaxially attached while being maintained, and a third rotating body member that is coaxially attached with a gap therebetween and constitutes the hydrodynamic slide bearing. The surfaces of the first to third rotating body members are combined to form a substantially closed space, and a charging means for charging the liquid metal lubricant into the closed space is the second A rotating anode X-ray tube is provided on a rotating member. In this rotary anode X-ray tube, the liquid metal lubricant that has passed through the end opening is confined in the substantially closed space, so that the liquid metal lubricant is more reliably prevented from leaking into the vacuum space. Is done. When such a structure of the rotating body is adopted, a part of the following guide means of the liquid metal lubricant is inserted into the gap between the second rotating body member and the third rotating body member for convenient use of the liquid metal lubricant. There exists an effect which can be guide | induced to the said input means.

  One of the present invention is that the guide means for guiding the liquid metal lubricant that has come out from the end opening to the path toward the vacuum space to the vicinity of the charging means provided in the second rotating body member is fixed. A rotary anode type X-ray tube according to the invention described above, wherein the rotary anode type X-ray tube is provided on at least one of the body and the rotating body. In this rotary anode type X-ray tube, since the liquid metal lubricant that has passed through the end opening is reliably guided into the closed space of the rotating body, the liquid metal lubricant scatters into the vacuum space. Without being put into the closed space.

  In one aspect of the present invention, the guide means has one end connected to the fixed body and the other end inserted into the gap between the second rotating member and the third rotating member. The rotary anode X-ray tube according to the invention is characterized in that it is constituted by an annular cover. In this rotary anode X-ray tube, the guide means can be realized with a simple structure.

  One aspect of the present invention is that the charging means provided in the second rotating member has a surface that is not wetted by the liquid metal lubricant, and the surface tension usually acts on the passage of the liquid metal lubricant. The rotary anode X-ray tube according to the above invention is characterized in that it comprises a one-way passage that is blocked by the liquid metal lubricant only when a centrifugal force is applied. In this rotary anode type X-ray tube, the liquid metal lubricant charged in the closed space of the rotating body is prevented from coming out again, and the liquid metal lubricant is prevented from reaching the vacuum space. The

  One aspect of the present invention is that the bonded surface forming the closed space includes a portion that is at a high temperature sufficient for the liquid metal lubricant to substantially react with the material of the surface and solidify. A rotary anode X-ray tube according to any one of the above inventions. In this rotary anode type X-ray tube, the liquid metal lubricant put into the closed space in the rotating body is solidified so that it does not come out again, and the liquid metal lubricant reaches the vacuum space. Is more reliably prevented.

  One aspect of the present invention is a rotary anode X-ray tube according to any one of the above inventions, a storage container for storing the rotary anode X-ray tube, and fixing the rotary anode X-ray tube to the storage container. A holding mechanism; a stator that applies rotational torque to the rotating body in the rotary anode X-ray tube from outside the vacuum vessel of the rotary anode X-ray tube; and a cathode that emits electrons in the rotary anode X-ray tube And a high voltage terminal for supplying a negative high voltage to the rotary anode type X-ray tube apparatus. This rotary anode X-ray tube apparatus not only simplifies the assembly process and the exhaust process as described above, but also prevents the liquid metal lubricant from reaching the vacuum space and has high reliability. A pipe device can be realized.

One aspect of the present invention is a vacuum container that defines a vacuum space, and a substantially cylindrical shape that is mechanically supported by a part of the vacuum container and protrudes into or penetrates the vacuum container. a fixed body having a central axis in the rotating body X-ray target and a portion comprising a coaxially fitted to the substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body is mounted coaxially And a method of manufacturing a rotary anode type X-ray tube comprising a spiral groove provided in a fitting portion between the fixed body and the rotating body and a hydrodynamic slide bearing having a liquid metal lubricant filled therein A first rotating member attached with the X-ray target, a second rotating member attached coaxially with a gap therebetween, and a coaxial member attached with a gap therebetween. The hydrodynamic slide bearing is constructed. Combining the third rotating body member to assemble the rotating body, and combining the surfaces of the first to third rotating body members to form a substantially closed space; A method of manufacturing a rotary anode type X-ray tube, comprising: a step of providing, on the second rotating body member, charging means for charging a liquid metal lubricant into the closed space. If this manufacturing method is adopted, the assembly process and exhaust process of the rotary anode X-ray tube can be simplified, and a rotary anode X-ray tube in which the liquid metal lubricant does not reach the vacuum space can be easily realized.

  By adopting the present invention, a rotary anode type X-ray tube device that uses a hydrodynamic slide bearing with a liquid metal as a lubricant and has a very large anode heat capacity and can withstand a large centrifugal force can be produced in a special process or special production. It can be mass-produced easily and stably without the need for equipment. Specifically, the gas contained in the liquid metal lubricant is separated inside the rotation mechanism, and a reversible passage of the liquid metal lubricant is formed that leads to the inside of the rotation mechanism and the inlet of the rotation mechanism. Because it employs a rotating mechanism that can exhaust only the gas to the outside and return the liquid metal lubricant to the internal bearing part, it is special in both the assembly process and exhaust process of the rotary anode X-ray tube There is no need to use a process or special equipment, and the process can be simplified. Furthermore, when the liquid metal lubricant passes through the bearing part due to an unexpected cause, the liquid metal lubricant is automatically returned to the inside of the bearing part. The liquid metal lubricant is irreversibly confined in a closed space provided in the rotating mechanism. As described above, since the liquid metal lubricant does not reach the vacuum space, even in actual use, the gas generated in the bearing portion during use is automatically exhausted, and the long-life rotary anode X with high reliability A tube and a rotary anode X-ray tube device using the same can be provided.

  The rotary anode type X-ray tube according to the present invention includes first and second radial bearings and two thrust bearings, each of which is composed of a hydrodynamic slide bearing using a liquid metal as a lubricant. Each of the rotating anodes includes a rotating mechanism that rotatably supports the rotating anode by generating a bearing force in a direction perpendicular to the rotating center axis of the rotating anode and a direction along the rotating center axis. Each of the slide bearings is adjacent to an annular reservoir communicating with the entire circumference of the bearing clearance at both ends, and a large number of these annular reservoirs are arranged in the circumferential direction directly below the slide bearing in parallel with the slide bearing. It is directly connected in the shortest distance by the lubricant passage provided in As a result, a lubricant flow path closed by the slide bearing, the annular reservoir, and the lubricant passage is formed in the entire bearing clearance of the slide bearing, so that the liquid metal lubricant flows into or slides into the slide bearing from every circumferential position. It can be discharged from the bearing. Even when the rotating body moves and the bearing gap increases or decreases, the amount of the liquid metal lubricant is automatically optimized. The liquid metal lubricant and the gas mixed therein can move around along the bearing gap of the slide bearing in the annular reservoir, and these are easily separated. Similarly, the lubricant passage has a large cross section so that the capillary effect can be ignored, and the liquid metal lubricant and gas can easily move. A space not filled with the liquid metal lubricant is included in the annular deep groove or in the lubricant passage, and the gas contained in the liquid metal lubricant easily moves and is separated from the liquid metal lubricant. As described below, the air is exhausted out of the rotating mechanism in a state where the space joins the space and expands to reduce the pressure.

  The annular reservoir has an annular deep groove having a deep groove with a narrow width and deeply cut from the surface of the fixed body, which is a fixed portion of the rotating mechanism, and a minute gap between the surface of the fixed body. An annular region surrounded by the surface of the rotating body having the opposite surface is included. The annular deep groove includes an annular bottom surface and two annular side surfaces connected to the bottom surface. A number of elongated holes that open to the annular side surface and extend in the tube axis direction are provided so as to be distributed along the outer side of the annular side surface. Each of these elongated holes is also opened on the annular side surface of another annular deep groove adjacent to the same plain bearing, and does not include a portion bent in the radial direction. These long holes and the annular deep grooves on both sides of the long holes are surrounded by the surface of the rotating body, and form a region that passes through the entire bearing clearance of the slide bearing. This is filled with a liquid metal lubricant having a volume corresponding to about 85% of the volume of this region. A region surrounded by the annular deep groove and the surface of the rotating body constitutes an annular reservoir, and the elongated hole constitutes a lubricant passage.

  A plurality of plain bearings configured as described above are provided in a direction along the central axis of the rotating body, and these are connected in series via the annular reservoir. As a result, when the rotating shaft is set in the horizontal direction, the slide bearing at the innermost part of the rotating mechanism is also connected in the horizontal direction, and some lubricant passages located vertically above reach the innermost part of the rotating mechanism. A space in the rotation mechanism connected horizontally can be formed. Because of this configuration, when the rotating shaft is in the horizontal direction, the liquid metal lubricant or the gas that has come out from somewhere on the member constituting the boundary wall is liquid metal lubricant. There is a passage that can be lifted vertically without entering the deep part of the waterline. The gas that has reached one of the annular reservoirs floats by buoyancy and joins the space inside the rotating mechanism. In this way, even if the pressure of the generated gas does not become abnormally high, it can be separated from the liquid metal lubricant and connected to the large space in the rotating mechanism. The gas accumulated in the space inside the rotating mechanism moves to the vacuum space in the vacuum vessel and is exhausted as described below.

  The terminal portion of the rotating body and the fixed body include surfaces facing each other with a minute gap, and the annular gap in this portion is referred to as an end opening. The rotating body and the fixed body include an extended portion extending from the annular reservoir closest to the end opening in the direction of the end opening, and the diameter thereof is substantially the first and second radial bearings. Is the same. In this extended portion, an annular forbidden band made of an opposing surface that is not wetted by the liquid metal lubricant is provided in a region extending in the direction of the end opening adjacent to the annular reservoir. This is configured such that each of the rotating body and the fixed body has a surface of, for example, titanium oxide or the like on the band-shaped surfaces facing each other with a minute gap. The clearance of this portion is slightly larger than the bearing clearance of the first and second radial bearings that are substantially responsible for the radial load, and can be prevented from mechanical contact with the surfaces of the opposing rotating bodies. ing. The annular metal band normally prevents the liquid metal lubricant from entering due to the surface tension generated in the liquid metal lubricant.

  An auxiliary third radial bearing is formed in the extended portion opposite to the annular reservoir adjacent to the annular forbidden band. It is preferable that the sliding bearing has a larger gap with the facing surface than the first and second radial bearings so that the facing surfaces do not come into contact with each other. There is a small diameter portion on the side closer to the end opening than the third radial bearing. In this small diameter portion, the fixed body has a shoulder and has a stepped outer diameter, and the surface of the rotating body faces the surface of the fixed body with a small gap. Of this small diameter portion, an annular gap facing the terminal end of the rotating body is the end opening, and communicates with the vacuum space defined by the vacuum vessel.

  The radial load of the rotating body is substantially supported by the first and second radial bearings, and the third radial bearing only generates an auxiliary bearing force. The third radial bearing is mainly responsible for pushing the liquid metal lubricant that has entered excessively into the annular reservoir and forming a temporary gas passage to be described later. The liquid metal lubricant is included in the gap and exhibits a certain level of bearing force. This serves to keep the bearing surface of the third radial bearing wet with the liquid metal lubricant at all times. The third radial bearing is provided with two sets of spiral grooves whose directions are opposite to each other. These include a first bearing groove that generates pressure to push the liquid metal lubricant in the direction of the annular reservoir when the rotating body rotates in the normal rotation direction, and the liquid metal lubricant in the direction of the end opening. And a second bearing groove that generates a pressure to be pressed. The first bearing groove occupies a larger area than the second bearing groove, and when the liquid metal lubricant is not newly supplied, the first bearing groove is formed in the second bearing groove region and a part of the first bearing groove region. Liquid metal lubricant has accumulated.

  When the rotating body is stationary, as described above, the liquid metal lubricant in the rotating mechanism is blocked by the annular forbidden band and prohibited from moving to the third radial bearing. Therefore, the space in the rotation mechanism is also connected to the annular forbidden band and is closed with the liquid metal lubricant in the third radial bearing. The liquid metal lubricant is attached to the third radial bearing. However, since the bearing gap is large, the liquid metal lubricant can easily move in the lateral direction when the rotating body is stationary. ing. In addition, since the depth and width of the bearing groove is large and the region where the liquid metal lubricant is small is wide, if the liquid metal lubricant moves in the direction along the central axis, it is broken and a temporary gas passage is easily formed. It has become. When the pressure in the internal space of the rotating mechanism increases to some extent, a small amount of liquid metal lubricant in the bearing gap of the third radial bearing is pushed in the direction of the shoulder in the region of the first bearing groove, and the fracture portion is The generated gas in the internal space of the rotating mechanism moves to the internal space of the vacuum vessel via the end opening. If the pressure in the space inside the rotating mechanism decreases, the state of the liquid metal lubricant is restored.

  When the rotating body is rotating at a high speed, the liquid metal lubricant in the annular reservoir is rotated by the rotation of the surface of the rotating body that is in contact, and the third force is applied by the centrifugal force acting on the liquid metal lubricant. Is pushed in the direction of the radial bearing and passes through the annular forbidden band and is pushed into the wide portion of the first bearing groove constituting the third radial bearing. At this time, in the third radial bearing, the pressure generated in the first bearing groove exceeds the pressure generated in the second bearing groove, and as a result, the pressure acts as a spiral pump to generate pressure opposite to the centrifugal force. The metal lubricant is prevented from leaking in the direction of the shoulder. The effect of this spiral pump is to prevent the leakage of the liquid metal lubricant even if the rotating anode type X-ray tube itself is revolved and the pushing force due to the centrifugal force generated in the liquid metal lubricant is added. Yes. The same applies when the pressure is increased due to gas expansion in the annular reservoir. When the force to push out such a liquid metal lubricant is reduced, the pushed liquid metal lubricant is returned to the annular deep groove via the annular forbidden band and returns to its original state. The liquid metal lubricant that has returned into the annular deep groove is supplied to the second radial bearing or moves through the lubricant passage into the other bearing portion. In other words, a reversible passage of the liquid metal lubricant from the third radial bearing through the annular forbidden band and the annular reservoir to any of the hydrodynamic slide bearings that substantially support the rotating body. Is configured. When the liquid metal lubricant passes through the third radial bearing and reaches the shoulder due to an unexpected reason, the liquid metal lubricant is subjected to centrifugal force at this portion and returned to the third radial bearing. And behave as described above.

  When the rotating body is rotating at a high speed, as described above, the liquid metal lubricant in the annular reservoir is pushed close to the surface of the rotating body by the centrifugal separation action, and the liquid metal lubricant is placed near the bottom surface of the deep groove. A space that does not exist is created. This space is connected to the space near the bottom surface of the adjacent annular deep groove and the outside of the rotating mechanism by a micro gas passage or filter provided near the bottom surface of the annular deep groove. Therefore, only when the rotating body is rotating, only the gas inside is communicated with the outside and can be discharged to the outside. Thus, even when the rotating body rotates at a high speed, the gas in the rotating mechanism is automatically exhausted.

  The amount of the liquid metal lubricant in the third radial bearing increases or decreases depending on the pressure applied to the liquid metal lubricant, but as described above, the liquid metal lubricant passes through the third radial bearing and passes through the third radial bearing. It does not move toward the end opening. The liquid metal lubricant that has passed through the third radial bearing due to an unforeseen cause is introduced by centrifugal force into the return hole provided in the rotating body by the introducing means when it reaches the small-diameter portion. Is passed through the return hole and returned to the third radial bearing. In this way, the liquid metal lubricant is prevented from passing through the end opening. Further, even when the liquid metal lubricant passes through the end opening for an unexpected reason, the path of the liquid metal lubricant is restricted by the guide means including an annular cover provided in the middle of the path to the vacuum space. , And is introduced and confined in a substantially closed space provided in the rotating body.

  As described above, the bearing characteristics are not substantially affected when the rotating body is stationary or rotating, and the liquid metal lubricant is ejected to the outside due to gas expansion or the like. Without being caused, the gas in the rotation mechanism is normally exhausted to the outside. At this time, the liquid metal lubricant does not reach the vacuum space, and a stable operation is ensured. Further, since the liquid metal lubricant is continuously exhausted without being leaked even during actual use, a reliable rotary anode X-ray tube can be provided. Hereinafter, the embodiment and operation of the present invention will be described more specifically and in detail using examples.

The configuration of the rotating anode X-ray tube of the present invention will be described with reference to FIGS. In these drawings, the same parts are denoted by the same reference numerals. FIG. 1 is a cross-sectional view showing the main part of a rotary anode X-ray tube according to the present invention, wherein 1 is a vacuum vessel for keeping the internal vacuum space 1a at a high vacuum, and 2 is in the vacuum vessel 1. The cathode 3 emits electrons, 3 is an X-ray target that emits X-rays when electrons emitted from the cathode 2 are incident, and 4 is an X-ray target that emits X-rays from the X-ray target 3. It is the X-ray irradiation window for taking out outside. In FIG. 1, 10 is a rotation mechanism for rotatably supporting the X-ray target 3, 20 is a rotation body for rotating the X-ray target 3 of the rotation mechanism 10 , and 30 is fitted to the rotation body 20 . a fixed body that rotatably supports a rotating body 20 is, 40 is a stator to impart a rotational force to the rotating body 20 from the outside of the vacuum container 1.

The rotating body 20 includes a target support body 21 on which the X-ray target 3 is mounted coaxially, a first rotating body member 22 that is coaxially joined to the target support body 21, and a coaxial shaft on the first rotating body member 22. Second rotating body member 23 attached to the second rotating body member, third rotating body member 24 coaxially attached to the second rotating body member 23, and coaxially attached to the second rotating body member 23. And a fourth rotary member 25. The X-ray target 3 is fixed to the tip of the target support 21 made of molybdenum alloy by the anode fixing screw 5, and the other end of the target support 21 is welded to one end 22 a of the first rotating member 22. The other end 22b of the first rotating member 22 is connected to one end 23a of the second rotating member 23 with a screw or the like, and the other end of the second rotating member 23 The portion 23b is connected to a part 24a of the third rotating member 24 by screws or the like (not shown). Further, a shielding cylinder 6 for shielding radiation heat from the X-ray target 3 is coaxially attached to the target support 21.

A rotor 26 is provided on the outer side of the first rotating body member 22 coaxially with the first rotating body member 22, and is joined by welding or the like in the vicinity of one end 22a of the first rotating body member 22. . The upper end portion of the third rotating body member 24 shown in the drawing forms a rotating body diameter small portion 24b, and a rotating lid 27 is connected to the upper end portion of the drawing by a screw or the like, and a rotating annular body is connected to the lower end portion of the drawing. 28 is connected by screws or the like. The rotor 26 is made of a material having a high electrical conductivity such as copper, and the lower half of the rotor 26 in the drawing has a diameter larger than that of the upper half in the drawing. It is shown in the lower half of the rotor 26 is adapted to provide a large rotational torque to the rotor 20 by the rotating magnetic field of the stator 40. The first rotating member 22 is made of a magnetic material such as pure iron, and is configured to be substantially parallel with a gap other than the joint portion with the rotor 26 to form a path for the rotating magnetic field. is doing. The second rotating body member 23 is made of a material having a small thermal conductivity such as an alloy (TNF) of 50 wt% iron and 50 wt% nickel, and the first rotating body member 22 and the third rotating body. A gap is maintained between the member 24 and other than the connecting portions. The third rotary member 24 and the rotary lid 27 are made of a material suitable for a sliding bearing such as iron alloy tool steel SKD11 (JIS standard), and the first rotary member 22 and the second rotary member 23 Between these, it is comprised without contact, maintaining a clearance gap except for the said connection part. The heat of the X-ray target 3 is conducted through the target support 21, the first rotating member 22 and the second rotating member 23 to the third rotating member 24 in which a slide bearing is formed. It has become.

The fixed body 30 has a fixed body portion 31 at the center of the figure, an upper shoulder 31a and a small fixed body diameter portion 31b at the upper end of the fixed body part 31 in the figure, and an anode fixing part at the lower end of the fixed body part 31 in the figure. 31c is formed. A disk-shaped partition plate 36 is fixed to the upper shoulder portion 31a, and the fixed body small diameter portion 31b is opposed to the upper shoulder portion 31a in a direction along the central axis CC ′. A bearing disc 32 is attached coaxially. The bearing disc 32 cannot be rotated relative to the fixed body portion 31 but is attached to the small fixed body portion 31b so as to be inclined at a small angle with respect to the central axis CC ′ of the fixed body portion 31. Yes. The lower end of the anode fixing portion 31c shown in the figure is fixed to a storage container of a rotary anode X-ray tube (not shown) containing insulating oil via an insulator (not shown) to constitute a rotary anode X-ray tube device. The fixed body portion 31 and the bearing disc 32 are made of a material suitable for a sliding bearing such as SKD11.

Will now be described in more detail with reference to FIGS. 2 and 3 of the fixed body 30 and the display non-cross in FIG. 2 is a sectional view enlarged to show the main portion of FIG. Herringbone pattern helical grooves GA1 and GA2 are provided on the upper and lower surfaces of the bearing disc 32 in the drawing, and the upper surface of the bearing disc 32 maintains a clearance of about 20 μm from the lower surface in the peripheral portion of the rotary lid 27. The lower surface of the bearing disc 32 is opposed to the upper surface of the rotating member protrusion 24c in which a part of the third rotating member 24 protrudes in an annular shape with a gap of about 20 μm. . Each spiral groove GA1, GA2 and each gap are filled with a liquid metal lubricant LM made of a gallium-indium-tin (Ga-In-Sn) alloy, which is a liquid during operation, each in the opposite direction. Two thrust bearings BA1 and BA2 are formed which generate dynamic pressure in a direction along the central axis CC ′. The liquid metal lubricant LM is not shown for ease of viewing except in FIGS. A large gap of about 1 mm is formed between the illustrated lower surface of the rotating body protrusion 24c and the illustrated upper surface of the partition plate 36, and the liquid metal lubricant LM is supplied thereto.

  There is a large gap DA2 of about 1 mm between the inner surface of the minimum diameter portion of the rotating body protruding portion 24c and the outer surface of the small fixed body diameter portion 31b, and the liquid metal lubricant LM is supplied thereto. The surface of the upper end portion in the figure of the small fixed body diameter portion 31b and the surface of the central portion of the rotary lid 27 are opposed to each other with a gap DS2 of at least about 0.5 mm, and the liquid metal lubricant LM is supplied to the gap DS2. ing. These two gaps DS1 and DS2 are communicated with each other by a lubricant passage RR3 including a hole provided in the bearing disc 32. The cylindrical outer surface parallel to the central axis CC ′ of the bearing disc 32 and the cylindrical inner surface of the rotary lid 27 facing the cylindrical outer surface face each other with a gap DA1 of about 1 mm, and the liquid metal lubricant LM Supplied and communicates with the two thrust bearings BA1 and BA2.

A lubricant passage RR4 including a large number of holes inclined so as to increase the distance from the central axis CC ′ as it approaches the bearing disc 32 is provided in the peripheral portion of the rotating body protrusion 24c. Since the lubricant passage RR4 is inclined, when it rotates, it acts to push the liquid metal lubricant LM in the direction of the gap DA1 by centrifugal force, and the liquid metal lubricant LM passes through the thrust bearings BA1 and BA2. Try to circulate. The magnitude of this action can be optimized by changing the tilt angle. When the rotational speed of the rotating body 20 is low and the holding action of the liquid metal lubricant LM in the thrust bearings BA1 and BA2 is smaller than the circulation action of the liquid metal lubricant LM by the centrifugal force, the liquid metal lubricant LM Circulates through the gap. When the rotational speed of the rotating body 20 is high and the holding action of the liquid metal lubricant LM in the thrust bearings BA1 and BA2 is large, the liquid metal lubricant LM in the thrust bearings BA1 and BA2 is in the thrust bearings BA1 and BA2. Trapped inside. When the liquid metal lubricant LM in the two thrust bearings BA1 and BA2 is insufficient or the size of the bearing gap changes, the amount of the liquid metal lubricant LM in the bearing gap is appropriately adjusted by the circulation action. It is to be refilled or discharged.

  The fixed body portion 31 has a substantially columnar shape, and two sets of herringbone-shaped bearing grooves GR1 and GR2 are provided on the outer peripheral surface of the cylindrical shape, and the third gap is maintained with a bearing gap of 20 to 30 μm. The liquid metal lubricant LM is supplied to the bearing grooves GR1 and GR2 and the bearing gap so as to face the inner surface of the rotating member 24, and first and second radials that generate dynamic pressure in the radial direction. The bearings BR1 and BR2 are configured. An annular deep groove DR 1, DR 2, DR 3 consisting of an annular deep groove is formed in the stationary body portion 31 between the first and second radial bearings BR 1, BR 2 and at the respective end portions. The boundary surfaces adjacent to the radial bearings BR1, BR2 of the annular deep grooves DR1, DR2, DR3 are tapered, and the depth of the annular deep grooves DR1, DR2, DR3 is continuously increased toward the radial bearings BR1, BR2. It is shallow, and the liquid metal lubricant LM supplied therein is easily supplied to the gap between the radial bearings BR1 and BR2. The annular deep grooves DR1, DR2, DR3 are covered with a cylindrical inner surface of the third rotating member 24, and these are filled with a liquid metal lubricant LM to form an annular reservoir.

  The annular deep grooves DR1, DR2, and DR3 open to shallow positions on the annular side walls, and are substantially parallel to the radial bearings BR1 and BR2, and connect the annular sidewall of the annular deep groove DR1 and the annular sidewall of the annular deep groove DR2. About 16 lubricant passages RR1 and about 16 lubricant passages RR2 connecting the annular side wall of the annular deep groove DR2 and the annular side wall of the annular deep groove DR3 are annularly arranged in the peripheral portion of the fixed body portion 31. Yes. Some of these lubricant passages RR1 and RR2 include small holes having a surface that is not wetted by the liquid metal lubricant LM, for example, filter-like gas is allowed to pass therethrough but the liquid metal lubricant LM is substantially passed therethrough. It may be replaced with a gas passage which is not allowed to be made. The lubricant passages RR1 and RR2 are long holes having a diameter of about 2 to 4 mm, and the capillary effect is ignored, so the inner surface may or may not be wet with the liquid metal lubricant LM. The gas separated from the lubricant LM, the gas contained in the liquid metal lubricant LM, or the liquid metal lubricant LM can pass therethrough.

A fixed body extending portion 31d extending from the radial bearings BR1 and BR2 while maintaining the diameter substantially the same is provided at a lower portion of the fixed body portion 31 in the figure, and a lower diameter small portion whose radius is reduced stepwise at the end thereof. 31e, and the lower diameter small portion 31e extends to the anode fixing portion 31c. In FIG. 3, a belt-like portion having a predetermined width, for example, 5 mm, and a width of about 0.1 mm on the surface of the fixed body extension portion 31d located below the lower wall DR3W in the figure of the annular deep groove DR3 located at the lowermost side in the figure. A belt-like portion having a predetermined width, for example, 5 mm, on the surface of the third rotating member 24 facing with a minute gap is formed as a surface not wetted by the liquid metal lubricant LM as described above. An annular forbidden band PR1 is formed which acts so as to prevent the passage thereof by the surface tension of the LM. The gap in this portion is larger than the gap between the radial bearings BR1 and BR2, and there is no mechanical contact, but the liquid metal lubricant LM is prevented from leaking when the rotating body 20 is stationary. The surface tension is large enough to work effectively.

In FIG. 3, there is a spiral groove GR3 on the surface of the fixed body extension 31d located below the annular forbidden band PR1, and this surface is opposed to the surface of the third rotating member 24 with a small gap. This is filled with the liquid metal lubricant LM, and constitutes a third radial bearing BR3. Of the helical groove GR3, the bearing groove GR3a located in the upper part of the figure is formed in a narrower range than the bearing groove GR3b located in the lower part of the figure. Accordingly, when there is no additional supply of the new liquid metal lubricant LM when the rotating body 20 is rotating, only the region BR3a composed of the bearing groove GR3a and a part of the bearing groove GR3b located above the spiral groove GR3 in the drawing is only provided. liquid metal lubricant LM is that is captured by the. In FIG. 3, when the liquid metal lubricant LM is added to the third radial bearing BR3, a force that pushes upward in the figure is generated due to an increase in pumping action in the bearing groove GR3b in the lower part of the spiral groove GR3 in the figure. In this way, the liquid metal lubricant LM is prevented from leaking through the annular forbidden band PR1. In order to make such an action more effective, it is preferable to further increase the pump action in the bearing groove GR3b located below the spiral groove GR3 in the figure. In order to realize this, for example, the gap in the lower portion of the bearing groove GR3b shown in the drawing below the spiral groove GR3 may be narrowed.

  As shown in FIG. 2, the annular side walls of the annular deep grooves DR1, DR2, DR3 open to positions close to the annular bottom surfaces, and are substantially parallel to the radial bearings BR1, BR2, and the annular sidewalls of the annular deep grooves DR1 About 16 gas passages RG1 connecting the annular side wall of the annular deep groove DR2 and about 16 gas passages RG2 connecting the annular side wall of the annular deep groove DR2 and the annular side wall of the annular deep groove DR3 are annular to the fixed body portion 31. Is arranged. Further, at the terminal end of the fixed body extension portion 31d, an opening is opened at the corner portion 31f connected to the lower-diameter small portion 31e, and the annular side wall DR3W of the annular deep groove DR3 closest to the fixed body extension portion 31d is located near the annular bottom surface. There are provided about 16 gas passages RG3 that are open at the same time. The gas passages RG1, RG2, and RG3 are made of an extremely thin tube or a sponge-like object having a surface that is not wetted by the liquid metal lubricant LM so that the liquid metal lubricant LM does not substantially pass but the gas passes. It has become. These can also be realized by making a relatively large hole and inserting a rod-shaped object having a narrow slit therein.

  In FIG. 2, a rotating annular body 28 having a surface facing the surface of the fixed body portion 31 with a clearance of about 0.1 mm is attached to the lower end of the third rotating body member 24 with screws or the like (not shown). It has been. The inner surface of the small inner diameter portion of the rotating annular body 28 has a depth of about 0.1 mm, and a separation ring made of annular grooves separated in a direction along the central axis CC ′ with a pitch of about 1 mm. A groove 28a is provided. This may be a spiral groove in the direction along the central axis C-C ′. A feedback hole 28c comprising a number of holes connecting the rotating body corner 28b generated by the connection between the rotating annular body 28 and the third rotating body member 24 and the separation annular groove 28a of the rotating annular body 28 is a central axis CC ′. Are arranged in an annular shape around. The separation annular groove 28a serves as introduction means for guiding the liquid metal lubricant LM to the return hole 28c. The lower end portion of the small inner diameter portion of the rotating annular body 28 is a terminal end portion 28e of the rotating body, and the annular gap between the inner surface and the outer surface of the lower small diameter portion 31e forms the end opening. is doing.

  The rotating annular body 28 is made of a material that is not wetted by the liquid metal lubricant LM, or the inner surface of the return hole 28c and the surface of the rotating annular body 28 facing the fixed body portion 31 are not wetted by the liquid metal lubricant LM. It is a surface. The surfaces of the lower-diameter small portions 31e of the fixed body portions 31 facing each other with a gap between them are also formed so as not to get wet. Since these gaps are larger than the gaps of the thrust bearings BA1, BA2 and the first and second radial bearings BR1, BR2, the surfaces facing each other are not mechanically contacted in any state. It has become.

As shown in FIG. 1, an annular cover 33 is attached in the vicinity of the anode fixing portion 31 c of the fixed body 30 , and the inner surface and the outer surface of the annular cover 33 are the rotating annular body 28 and the third rotating body member 24. Are provided opposite to each other and the inner surfaces of the fourth rotating member 25 and the second rotating member 23 with a gap therebetween. An annular body 34 is hermetically connected to the stationary body 30 by welding or the like in the vicinity of the anode fixing portion 31 c and below the annular cover 33 in the drawing, and the peripheral portion is an insulating portion of the vacuum vessel 1 through a sealing ring 35. And the interior is evacuated to form a vacuum space 1a.

A method of enclosing the liquid metal lubricant LM in the rotation mechanism 10 will be described with reference to FIG. First, the fixed body portion 31 of the fixed body 30 is inserted into the third rotating body member 24 so that the central axes CC ′ coincide with each other, and the illustrated upper end portion of the fixed body small diameter portion 31b is the rotating body protruding portion 24c. The lower wall DR3W of the annular deep groove DR3 located at the lower side of the central hole of the figure and located at the lowermost side of the figure is temporarily fixed in a state of being located above the lower end 24d of the rotating body. At this time, the bearing grooves GR1 and GR2 are preferably wetted in advance with the liquid metal lubricant LM. In this state, since the central hole of the rotating body protrusion 24c is in an air core state in the upper part of the figure, the liquid metal lubricant LM is dropped from the hole and inserted in the atmosphere. The amount of the liquid metal lubricant LM to be filled is appropriately 80% or more and less than 100% of the space surrounded by the third rotating body member 24 and the fixed body 30 , but is preferably about 85%. The fixed body portion 31 is provided with annular deep grooves DR1, DR2 and DR3 and a large number of lubricant passages RR1 and RR2 for connecting them, and also operates as a gas passage having a large number of large cross sections. The gas inside the metal lubricant LM is easily replaced by gravitational acceleration. As will be described later, even if gas remains in the bearing gap and other parts, or even if the liquid metal lubricant LM itself contains gas, these gases are obstructed by the liquid metal lubricant LM during the exhaust process. Easily exhausted without For this reason, special processes such as work in a vacuum vessel as disclosed in Japanese Patent Application Laid-Open No. 9-35633 and Japanese Patent Application Laid-Open No. 5-12997 are also special cases such as a vacuum vessel for assembly. No equipment is required.

  As described above, since the annular forbidden band PR1 located at the lowermost position in FIG. 3 is a surface that does not get wet with the liquid metal lubricant LM, the inserted liquid metal lubricant LM cannot enter this gap. It accumulates in the annular deep groove DR3 located at the lowermost position. Further, the inserted liquid metal lubricant LM is filled in the lubricant passage RR2 while being replaced with a gas in a plurality of annularly connected lubricant passages RR2. Similarly, the annular deep groove DR2, located in the upper part of the figure, the lubricant passage RR1, and the annular deep groove DR1 are sequentially filled with the liquid metal lubricant LM. At this time, the liquid metal lubricant LM is prevented from entering the gas passages RG1, RG2, RG3 by the surface tension.

After the predetermined amount of the liquid metal lubricant LM is inserted, the rotary annular body 28 is pushed up into the third rotary member 24 from below in the figure and fixed by screws or the like (not shown). At this time, the fixed body portion 31 is relatively moved until the illustrated upper surface of the partition plate 36 attached to the upper shoulder portion 31a of the fixed body 30 comes close to the illustrated lower surface of the rotating body protruding portion 24c. In this state, the upper end portion of the fixed body small-diameter portion 31b is positioned above through the rotating body protruding portion 24c. A bearing disc 32 is inserted into this portion and attached so as not to move in the direction along the central axis CC ′ with a stopper or the like and to rotate relative to the fixed body portion 31. Next, the rotary lid 27 is attached to the third rotary member 24 and screwed.

Next, a method for assembling the rotary anode type X-ray tube will be described with reference to FIG. A part 24 a of the third rotating member 24 assembled as described above is fixed to the other end 23 b of the second rotating member 23 with a screw or the like. The other end 22b of the first rotating member 22 to which the X-ray target 3, the shielding cylinder 6, the target support 21, and the rotor 26 are attached, and one end of the second rotating member 23 assembled as described above. The part 23a is fixed with screws or the like. Next, the annular cover 33 is attached to the anode fixing portion 31 c and the fourth rotating body member 25 is fixed to the one end portion 23 a of the second rotating body member 23. In the vicinity of the anode fixing portion 31c, the annular body 34 is connected to the fixing body 30 in an airtight manner below the annular cover 33 by welding or the like, and the peripheral portion is connected to the vacuum vessel 1 through the sealing ring 35 in an airtight manner. The inside is evacuated and assembled into a rotating anode X-ray tube. A method for exhausting the rotary anode X-ray tube assembled in this way will be described below.

In exhausting the rotary anode X-ray tube of the present embodiment, it is not necessary to change the direction of the tube axis of the rotary anode X-ray tube in the entire exhaust process, but the central axis CC ′ of the anode, that is, It is preferable that the tube axis CC ′ of the rotary anode type X-ray tube be in the horizontal direction. FIGS. 4 and 5 are sectional views showing the distribution of the liquid metal lubricant LM in the rotation mechanism 10 when the tube axis CC ′ is set in the horizontal direction. FIG. 4 shows a case where the rotating body 20 is stationary, and FIG. 5 shows a case where the rotating body 20 is rotating at a high speed.

First, the case where the rotating body 20 is stationary will be described with reference to FIG. Each slide bearing BA1, BA2, BR1, BR2 is filled with a liquid metal lubricant LM in each bearing gap and each bearing groove. Third radial bearing BR3 is the are filled with liquid metal lubricant LM only in the region of a portion as has been insufficient liquid metal lubricant LM in the other portions. The liquid metal lubricant LM is about 85% of the volume of the region surrounded by the rotating body 20 and the fixed body 30, and at least one of the lubricant passages RR1 and RR2 is the water line LL of the liquid metal lubricant LM. because it is arranged around the fixed body 30 to also positioned vertically above the at least one each of the lubricant passage RR1, RR2 in the illustrated upward there are those that are not filled with a liquid metal lubricant LM. The gas passages RG1, RG2, RG3 are closed by the liquid metal lubricant LM in the annular reservoir formed of the annular deep grooves DR1, DR2, DR3, and the clearance of the annular forbidden band PR1 with the third radial bearing BR3 as a boundary, The portions located vertically above the draft line LL in the annular deep grooves DR1, DR2, DR3, the flat gaps DS1, DS2, the lubricant passage RR4, and the annular gap DA1 form a connected rotation mechanism internal space VA1.

  The left side of the region BR3b in the third radial bearing BR3 communicates with the internal space 1a of the vacuum vessel 1 so that gas can pass therethrough. When the internal space 1a of the vacuum vessel 1 is evacuated by a vacuum pump (not shown) through an exhaust pipe (not shown), a pressure difference is generated between the internal space 1a of the vacuum vessel 1 and the space VA1 in the rotating mechanism, and the third The liquid metal lubricant LM held in the region BR3a of the radial bearing BR3 expands in the direction of the region BR3b and breaks to form a temporary gas passage, and the internal space 1a of the vacuum vessel 1 and the rotation mechanism internal space VA1 The space is coupled as an exhaust path, and the space in the internal space VA1 is gradually exhausted. Since the liquid metal lubricant LM and the gas are roughly separated and the movement of the liquid metal lubricant LM is facilitated, and the gas contained in the liquid metal lubricant LM is easily separated, the gas Therefore, there is no inconvenience that the liquid metal lubricant LM is blown off due to the rapid expansion of the liquid. The liquid metal lubricant LM is expanded in the lubricant passages RR1, RR2 or in the annular deep groove DR1, by the expansion of the gas partially enclosed by the liquid metal lubricant LM in the liquid metal lubricant LM or in the internal space VA1 of the rotation mechanism. When moved in DR2 and DR3 and merged with the rotation mechanism internal space VA1, the volume of the rotation mechanism internal space VA1 is large, so that the gas becomes low in pressure and passes through the gas passage as described above to pass through the vacuum vessel. It moves to 1 internal space 1a. Even if a part of the liquid metal lubricant LM is moved, the other liquid metal lubricant LM passes through one of the lubricant passages RR1 and RR2, and the level of the waterline does not substantially change.

Since the rotation mechanism internal space VA1 is kept at room temperature until it is evacuated to a high vacuum, the bearing surface is not substantially oxidized, and a liquid metal as disclosed in JP-A-4-363844 is disclosed. There is no need for special treatment such as preparing a reaction layer with the lubricant LM in advance in a vacuum. When the stator 40 is energized and the rotator 20 is rotated at a low speed in a state where a high vacuum is reached, the liquid metal lubricant LM is sucked into the bearing gaps from the annular reservoir formed by the annular deep grooves DR1, DR2, DR3. As a result, the entire bearing surface gets wet well and the liquid metal lubricant LM in the annular deep grooves DR1, DR2, DR3 and the lubricant passages RR1, RR2 circulates to separate the gas contained in the liquid metal lubricant LM. The gas is exhausted through the gas passage.

In the state where the bearing surface is completely wet as described above and the space VA1 in the rotation mechanism is sufficiently high in vacuum, the temperature in the rotation mechanism 10 is increased from the outside of the vacuum vessel 1 by high-frequency heating or an electric furnace. When the gas is gradually increased, the gas confined in the liquid metal lubricant LM and the gas adsorbed by the material constituting the bearing are released, and through the internal space 1a of the vacuum vessel 1 in the same manner as described above. The air is exhausted by a vacuum pump (not shown). At this time, the amount of the liquid metal lubricant LM is much larger than the amount necessary for each dynamic pressure type slide bearing BA1, BA2, BR1, BR2 to operate normally, and the liquid metal lubricant LM circulates, so that the exhaust gas is exhausted. The oxidation of the liquid metal lubricant LM itself in the process is not a problem.

When each bearing surface is completely wetted with the liquid metal lubricant LM, it becomes difficult for the gas to move through the bearing gap. However, in the present invention, a large number of lubricant passages RR1, which bypass each slide bearing, are used. RR2 is included, and at least one of the lubricant passages RR1 and RR2 is in a state in which the gas can freely move without applying excessive pressure to the liquid metal lubricant LM in the slide bearing. Exhausted. Further, as will be described later, when the rotating body 20 is rotating, as shown in FIG. 5, a passage is formed in which the liquid metal lubricant LM covering the openings of the gas passages RG1, RG2, RG3 is removed. The inside of the rotation mechanism is easily exhausted. Therefore, there is no need for a step of forcibly changing the bearing gap during the exhaust process, as disclosed in, for example, Japanese Patent Application Laid-Open No. 5-290734. As described above, the rotary anode X-ray tube according to the present invention can be easily manufactured in a short time without requiring any special apparatus or special operation.

Next, an operation when the tube axis CC ′ of the completed rotary anode X-ray tube is in the horizontal direction will be described. The thrust bearing BA1 communicates from both sides to the flat gap DS2 and the annular gap DA1 to which the liquid metal lubricant LM is supplied, and the liquid metal lubricant LM is exchanged. The flat gap DS2 to which the liquid metal lubricant LM is supplied communicates with the flat gap DS1 to which the liquid metal lubricant LM is supplied through the lubricant passage RR3 and the annular gap DA2, and the flat gap DS1 is connected to the lubricant passage RR4. Therefore, the thrust bearing BA1 forms a closed circulation path without passing through another dynamic pressure type sliding bearing. The lubricant passage RR4 is provided in the rotating body protrusion 24c so as to be inclined from the tube axis CC ′, and the liquid metal lubricant LM in the lubricant passage RR4 receives the centrifugal force and travels toward the annular gap DA1. Under pressure. As described above, when the liquid metal lubricant LM is filled in the annular gap DA1 and the thrust bearing BA1 and sufficient pressure is generated in the thrust bearing BA1, the liquid metal lubricant LM in the lubricant passage RR4 is It only causes an increase in pressure in the liquid metal lubricant LM and has little effect on the operation of the thrust bearing BA1. If a space that is not filled with the liquid metal lubricant LM is generated in the annular gap DA1, the liquid metal lubricant LM in the lubricant passage RR4 is moved by the centrifugal force so as to fill the annular gap DA1. When an external force in the direction along the central axis CC ′ is applied to the rotating body 20 and the clearance of the thrust bearing BA1 changes, the liquid metal lubricant LM moves through the circulation path, whereby the thrust bearing BA1. The amount of the liquid metal lubricant LM in the inside is optimized.

  Similarly, the outside of the thrust bearing BA2 communicates with the annular gap DA1 to which the liquid metal lubricant LM is supplied, and the inside of the thrust bearing BA2 communicates with the flat gap DS1 through the annular gap DA2. The annular gap DA1 is connected to the lubricant passage. Since it communicates with the flat gap DS1 through RR4, the thrust bearing BA2 constitutes a closed circulation path without passing through other dynamic pressure type slide bearings. The exchange of the liquid metal lubricant LM in the thrust bearing BA2 is performed in the same manner as the liquid metal lubricant LM in the thrust bearing BA1, and the respective operations are performed independently.

Since the bearing disc 32 can be inclined with respect to the central axis CC ′ of the fixed body 30 when the angle of the rotation center axis of the rotary body 20 is slightly shifted, each of the thrust bearing BA1 and the thrust bearing BA2 The gap does not need to be inclined in the radial direction, and stable operation is guaranteed. This effect is obtained when the distance between the first and second radial bearings BR1 and BR2 is relatively short, or when the gap between the bearing surfaces of the first and second radial bearings BR1 and BR2 is relatively large, This is noticeable when the diameter of the thrust bearings BA1 and BA2 is relatively large. Furthermore, even if the clearance between the respective bearing surfaces of the thrust bearings BA1 and BA2 is narrower than in the prior art, the opposing bearing surfaces are always kept in parallel, so that a large bearing pressure is stably generated. Therefore, since the bearing clearances of the thrust bearings BA1 and BA2 can be made narrower than in the prior art, the moving amount of the rotating body 20 in the tube axis CC ′ direction can be limited to be smaller.

Next, the operation of the first radial bearing BR1 will be described with reference to FIGS. At both ends of the first radial bearing BR1, there are an annular deep groove DR1 and an annular deep groove DR2 having a depth of about 4 mm and a width of about 2 mm to which the liquid metal lubricant LM is supplied. These are formed by a number of lubricant passages RR1. They are connected to form a closed circuit. When the tube axis CC ′ is horizontal and the rotating body 20 is stationary, the amount of the liquid metal lubricant LM is determined so as to create a space VA1 that is not filled with the liquid metal lubricant LM as shown in FIG. In addition, at least a part of the lubricant passage RR1 forms a through passage.

FIG. 5 shows the distribution state of the liquid metal lubricant LM when the tube axis CC ′ is in the horizontal direction and the rotating body 20 is rotating at a high speed. While the rotating body 20 is rotating, a force is generated in the bearing groove and the bearing gap of the first radial bearing BR1 so as to be sucked from the annular deep groove DR1 and the annular deep groove DR2 and push the liquid metal lubricant LM. A large bearing force is generated in the bearing gap, and the liquid metal lubricant LM is substantially captured in the slide bearing and cannot substantially move in the tube axis direction. When the rotary body 20 is rotating, when a radial external force is applied to the rotary body 20 to change the size of the bearing gap, or when the opposing bearing surface is inclined with respect to the fixed body surface, the annular deep groove DR1 and the annular deep groove The liquid metal lubricant LM flows in or out from DR2, and the liquid metal lubricant LM in the radial bearing BR1 does not become excessive or insufficient. In this case, since these form a closed circulation path, the characteristics of other hydrodynamic slide bearings are not substantially affected, so that stable operation can be obtained. This situation also applies to the radial bearing BR2 and is the same regardless of the direction of the tube axis CC ′.

When the inner surface of the third rotating member 24 facing the annular deep grooves DR1, DR2, DR3 with a small gap of about 30 μm is rotating at high speed, liquid metal lubrication in the annular deep grooves DR1, DR2, DR3 is performed. The agent LM rotates and generates pressure inside by centrifugal force and is affixed to the outer peripheral portion, and is pushed into the radial bearings BR1 and BR2, the lubricant passages RR1, RR2 and RR4, the annular forbidden band PR1, and the like. Receive power. In this way, the lubricant passages RR1 and RR2 are substantially sealed and the gas does not easily pass through, but the bottom of the annular deep grooves DR1, DR2 and DR3 where the liquid metal lubricant LM is substantially eliminated is the gas passage. The rotation mechanism internal space VA2 is formed by being connected by RG1 and RG2 and totally connected. Since the rotation mechanism internal space VA2 communicates with the end opening by the gas passage RG3, the gas in the rotation mechanism 10 is automatically exhausted even when the rotating body 20 is rotating. As described above, the exhaust process has the same effect.

As described above, in the case where a gas suddenly appears in a deep part of the rotating body 20 , for example, in the flat gap DS2 and a partial high pressure is generated due to its expansion or the like, a part of the liquid metal lubricant LM and gas pass through passages other than the slide bearing, for example, the lubricant passage RR3 and the flat gap DS1 and flow into the annular deep groove DR1, but the volume of these portions is sufficiently large, so the liquid metal lubricant LM And gas are separated, the pressure of the gas decreases in the combined space VA2, passes through the gas passage RG3, moves to the vacuum space 1a in the vacuum vessel 1, and is obtained by a getter (not shown) in the vacuum vessel 1 Removed. Such a phenomenon is likely to occur immediately after the exhaust process or immediately after the start of actual use.

As described above, when the rotating body 20 is rotating at a high speed, the liquid metal lubricant LM in the annular deep groove DR3 receives centrifugal force and is pushed in the direction of the annular forbidden band PR1, and the surface tension here is reduced. It is overcome and fed into the third radial bearing BR3. The supplied liquid metal lubricant LM is pushed to the region BR3b of the third radial bearing, and the pump action for pushing the liquid metal lubricant LM in this portion in the direction of the annular deep groove DR3 is superior. , A boundary surface is formed somewhere in the region BR3b and is balanced. When the rotating anode type X-ray tube of the present invention is applied to a CT scanner and is revolved at a high speed around the central axis of the apparatus spaced apart from the tube axis CC ′, the rotating anode The entire type X-ray tube receives a large centrifugal force, and naturally, a strong centrifugal force acts on the liquid metal lubricant LM, and the force for pushing the liquid metal lubricant LM into the third radial bearing BR3 increases. Both forces are balanced by moving the boundary surface within the region BR3b. In this way, even during actual use, the liquid metal lubricant LM does not leak out from the third radial bearing BR3. So far, the case where the tube axis CC ′ is horizontal has been described, but the direction of the tube axis CC ′ can be arbitrarily set after the rotation mechanism internal spaces VA1, VA2 are sufficiently high in vacuum.

If the liquid metal lubricant LM passes through the third radial bearing BR3 and reaches the separation annular groove 28a via the rotating body corner portion 28b and the rotating body diameter small corner portion for an unexpected reason, The liquid metal lubricant LM is pressed against the inner surface of the separation annular groove 28a by the centrifugal force when the rotating body 20 rotates. The pressed liquid metal lubricant LM is pushed back by the centrifugal force into the return hole 28c formed by a large number of holes opened in the separation annular groove 28a and the rotating body corner 28b, and is pushed back to the rotating body corner 28b. When the amount reaches a certain level or more, it is returned to the annular deep groove DR3 as described above by the third radial bearing BR3 in the vicinity. The return hole 28c is composed of a large number of small holes made of an inner surface that is not wetted by the liquid metal lubricant LM. Normally, the liquid metal lubricant LM does not enter and moves only when a strong centrifugal force is applied. It can be done. Therefore, the liquid metal lubricant LM passes one way through the return hole 28c. The return holes 28c are also provided at different positions in the direction along the central axis CC ′ of the separation annular groove 28a in the same manner as described above, and the probability that the liquid metal lubricant LM is returned as described above is extremely high. It is high.

  Further, when the liquid metal lubricant LM passes through the end portion 28e of the rotating body for an unexpected reason, the passage is restricted by the annular cover 33, so that the leaked liquid metal lubricant LM is not subjected to the third rotation. It is guided to the annular cover tip 33a of the annular cover 33 in the gap between the body member 24 and the second rotating body member 23, and is centrifuged through the small hole 23c of the second rotating body member 23 formed in the vicinity thereof. The force is confined in a closed space surrounded by the second rotating member 23, the first rotating member 22, and the third rotating member 24. The small hole 23c is a charging means for charging the liquid metal lubricant LM into the closed space, and the annular cover 33 is a guiding means for guiding the liquid metal lubricant LM to the vicinity of the charging means. Since the first rotating member 22 is at a high temperature, the liquid metal lubricant LM contained therein reacts with the surrounding material and is fixed. The liquid metal lubricant LM that has not entered the small hole 23 c is prevented from moving to the vacuum space 1 a of the vacuum vessel 1 by the fourth rotating body member 25. As described above, in the rotary anode X-ray tube of this embodiment, the liquid metal lubricant LM is practically prevented from leaking into the vacuum space 1 a in the vacuum vessel 1.

Another embodiment will be described with reference to FIG. In FIG. 6, parts corresponding to those in FIGS. 1 to 5 are denoted by the same reference numerals. In this embodiment, a substantially cylindrical rotating body 20 is coaxially attached to a fixed body 30 provided so as to penetrate through the vacuum vessel 1 with a small bearing gap, and is positioned substantially at the center of the rotating body 20. A line target 3 is attached. First and second radial bearings BR1 and BR2 made of hydrodynamic slide bearings using a liquid metal as a lubricant are provided on both sides of the X-ray target 3, and the structure and operation thereof are the same as in the other embodiments. Since there is, description is abbreviate | omitted. Each of the first and second radial bearings is sandwiched between two annular deep grooves, which are coupled to each other through the lubricant passages RR1 and RR2 as in the other embodiments. The upper end portion and the lower end portion of the rotary body 20 and the fixed body 30 are respectively provided with the end openings, and these portions have a third radial bearing BR3 and a rotary annular body 28 shown in FIGS. Similar ones are provided and operate as described above. In this embodiment, since the end openings are provided at the upper and lower portions in the drawing, the lubricant passage connecting the annular deep groove DR2 and the annular deep groove DR3 located in the center of the fixed body 30 is omitted. Is preferred. Further, the gas passage is also omitted. Since the fixed body 30 is provided through the vacuum vessel 1, a cooling medium passage (not shown) can be provided through the fixed body 30 . This embodiment is suitable for receiving a larger external force than the other embodiments. The first embodiment is suitable for a so-called neutral grounding power source, but this embodiment is suitable for a so-called anode grounding power source.

Another embodiment will be described with reference to FIG. In FIG. 7, parts corresponding to those in FIGS. 1 to 5 are denoted by the same reference numerals. In the present embodiment, an annular fixed body lid 37 is attached to a portion corresponding to the fixed body extension portion 31d in the first embodiment, and a fixed annular body 38 is inserted and fixed. The fixed body lid 37 has an annular deep groove DR3 projecting annularly at a portion close to the surface of the third rotary member 24, and restricts the width of the annular opening DR3a of the annular deep groove DR3. The outer surface of the fixed body lid 37 and the inner surface of the third rotating member 24 opposed to the outer surface of the fixed body lid 37 are not wetted with the liquid metal lubricant LM. Forming. There is a bearing groove GR3 on the outer surface of the fixed annular body 38, and this outer surface and the inner surface of the third rotating member 24 facing this with a minute gap therebetween are the third radial bearings BR3. Is configured. The other annular deep grooves DR1 and DR2 have the same structure, but the others are the same as those in the first embodiment, and a description thereof will be omitted. Of course, the fixed body lid 37 and the fixed annular body 38 may be formed integrally with the fixed body 31. In this embodiment, since the annular opening DR3a of the annular deep groove DR3 is narrow, it is possible to prevent the liquid metal lubricant LM in the annular deep groove DR3 from moving abnormally when the rotating body 20 rotates at an extremely high speed. Further, it is possible to prevent the liquid metal lubricant LM from jumping directly into the annular forbidden band PR1 when the gas in the rotating mechanism suddenly comes out, and the operation is stable. It may be composed.

Another embodiment will be described with reference to FIG. 8, parts having the same functions as those in FIGS. 1 to 5 are denoted by the same reference numerals. In the present embodiment, an annular fixed body lid 37 is attached and fixed to a portion corresponding to the fixed body extension portion 31d in the first embodiment. The outer peripheral surface of the fixed body lid 37 and the inner peripheral surface portion of the third rotating body 24 having a minute gap with the fixed body lid 37 are formed with an annular forbidden band PR1 composed of a surface not wetted by the liquid metal lubricant LM. The illustrated left end surface of the fixed lid 37 is an annular plane perpendicular to the central axis CC ′, and a spiral groove GA3 is provided on this surface. The right end face in the figure of the annular rotator 28 is provided to face this surface with a minute bearing gap. These surfaces are wetted by the liquid metal lubricant LM, and the liquid metal lubricant LM is contained in the bearing gap, and these constitute a third thrust bearing BA3 which is an auxiliary sliding bearing. . The bearing gap of the third thrust bearing BA3 is larger than the bearing gap of the first and second thrust bearings BA1 and BA2 that substantially support the rotating body 20 in the direction along the central axis CC ′. The opposing bearing surfaces of the third thrust bearing BA3 are not in mechanical contact under any conditions. The spiral groove GA3 includes a bearing groove GA3b that tries to move the liquid metal lubricant LM in the large diameter direction and a bearing groove GA3a that tries to move the liquid metal lubricant LM in the small diameter direction. The radius Rc serving as the boundary is a value close to the outer radius Ra of the fixed body lid 37 and is much larger than the average value of the inner radius Rb and the outer radius Ra of the fixed body lid 37. Normally, the liquid metal lubricant LM is maintained only in the large diameter portion in the bearing gap of the third thrust bearing BA3. When the liquid metal lubricant LM is pushed into the third thrust bearing BA3 after passing through the annular forbidden band PR1, the pressure in the large diameter direction increases and the liquid metal lubricant LM is further reduced in the small diameter direction. The movement which becomes becomes is stopped. When the pressure to push the liquid metal lubricant LM into the third thrust bearing BA3 decreases, the pushed liquid metal lubricant LM is returned to the annular deep groove DR3 via the annular forbidden band PR1, Return to the original state. The liquid metal lubricant LM that has returned to the annular deep groove DR3 is supplied to the second radial bearing BR2, or moves into the other bearing portion through the lubricant passage RR3. The outer surface of the lower-diameter small portion 31e of the fixed body portion 31 and the inner surface of the annular rotating body 28 facing this with a minute gap are formed so as not to get wet with the liquid metal lubricant LM. This embodiment corresponds to the case where the third radial bearing in the first embodiment is replaced with a third thrust bearing.

  Although the invention has been described with reference to embodiments and examples, the invention is not limited to the embodiments and examples illustrated herein, and various modifications can be made without departing from the spirit and scope of the invention. It should be understood that various embodiments are possible and that various changes and modifications can be made. For example, the annular reservoir has the same effect as long as it is connected in the circumferential direction even in a deep groove having a polygonal cross section provided in the fixed body, and is included in the present invention. Further, both the rotating body and the fixed body may have an annular deep groove. Even if a part of the circumference of the annular deep groove is embedded, the liquid metal lubricant LM is included in the present invention as long as it can move substantially in an annular shape. Even if the lubricant passage is slightly inclined, the same effect can be obtained if it is set so that a gas passage located above the waterline of the liquid metal lubricant LM is generated. The return hole can also be realized by dividing the annular rotating body 28 into cone-shaped multilayer portions and overlapping them.

  The rotary anode X-ray tube of the present invention can be effectively used as an X-ray generation source for an X-ray CT scanner and other radiation equipment. In particular, a hydrodynamic slide bearing using a liquid metal lubricant is adopted, and an extremely large bearing force can be obtained. Therefore, for high-speed scanning X-ray CT scanners that have a large anode heat capacity and can revolve at high speed. Suitable for X-ray tube device. This type of rotary anode X-ray tube reported heretofore has been expensive because it was manufactured by a special manufacturing method using special equipment, but the rotary anode X-ray tube of the present invention is bad. Since liquid metal lubricant is prevented from leaking even in the environment, an inexpensive and highly reliable rotary anode X-ray tube with high capacity can be provided without the need for special manufacturing equipment and manufacturing processes. The industrial utility value is high.

It is a longitudinal cross-sectional view which shows a part of rotating anode type X-ray tube concerning this invention. It is the longitudinal cross-sectional view which shows a part of rotation mechanism used for the rotating anode type X-ray tube concerning this invention, and a cross-sectional view. It is the figure which represented a part of rotation mechanism used for the rotation anode type X-ray tube concerning this invention in the cross section. It is the longitudinal cross-sectional view and cross-sectional view which show a part of rotation mechanism used for the rotary anode type X-ray tube concerning this invention, and is a figure explaining the effect | action of a slide bearing. It is the longitudinal cross-sectional view and cross-sectional view which show a part of rotation mechanism used for the rotary anode type X-ray tube concerning this invention, and is a figure explaining the effect | action of a slide bearing. It is a longitudinal cross-sectional view which shows a part of other Example of the rotating anode type | mold X-ray tube concerning this invention. It is a longitudinal cross-sectional view which shows a part of rotation mechanism in the further another Example of the rotating anode type X-ray tube concerning this invention. It is the figure which shows the longitudinal cross-sectional view which shows a part of rotation mechanism in the further another Example of the rotating anode type | mold X-ray tube concerning this invention, and the shape of a bearing groove.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum container 1a Internal space 2 Cathode 3 X-ray target 4 X-ray irradiation window 5 Anode fixing screw 6 Shielding cylinder
10 rotation mechanism
20 Rotating Body 21 Target Support Body 22 First Rotating Body Member 22a Rotating Body One End 22b Rotating Body Other End 23 Second Rotating Body Member 23a Rotating Body One End 23b Rotating Body Other End 23c Small Hole 24 Third Rotating body member 24a Rotating body part 24b Rotating body diameter small portion 24c Rotating body projecting portion 24d Rotating body lower end 25 Fourth rotating body member 26 Rotor 27 Rotating lid 28 Rotating annular body 28a Separating annular groove 28b Rotating body corner 28c Feedback hole 28e End of rotating body
30 fixed body 31 fixed body portion 31a upper shoulder portion 31b fixed body small diameter portion 31c anode fixed portion 31d fixed body extension portion 31e lower diameter small portion 31f corner 32 bearing disc 33 annular cover 33a annular cover tip 34 annular body 35 Sealing ring 36 Partition plate 37 Fixed annular lid 38 Fixed annular body 40 Stator BA1 Thrust bearing BA2 Thrust bearing BR1 First radial bearing BR2 Second radial bearing BR3 Third radial bearing BR3a Third radial bearing area BR3b First Region of radial bearing 3 DA1 Annular gap DA2 Annular gap DR1 Annular deep groove DR2 Annular deep groove DR3 Annular deep groove DR3a Annular opening of the annular deep groove DR3W Announced lower wall of the annular deep groove DR3 DS1 Flat gap DS2 Flat gap GA1 Thrust bearing groove GA2 Thrust bearing groove G2 3 Thrust bearing groove GA3a Thrust bearing groove GA3b Thrust bearing groove GR1 Radial bearing groove GR2 Radial bearing groove GR3 Radial bearing groove GR3a Radial bearing groove GR3b Radial bearing groove LL Liquid metal lubricant draft line LM Liquid metal lubricant R G1 Passage RG2 Gas passage RG3 Gas passage RR1 Lubricant passage RR2 Lubricant passage RR3 Lubricant passage RR4 Lubricant passage VA1 Rotating mechanism inner space VA2 Rotating mechanism inner space

Claims (19)

A vacuum vessel that defines a vacuum space, and a fixed body that is mechanically supported by a part of the vacuum vessel and protrudes into the vacuum vessel or penetrates the vacuum vessel and has a central axis When the rotating body X-ray target is attached coaxially to and partially includes a coaxially mated substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body, the fixed body and the a spiral groove provided in the fitting portion between the rotary member, the rotary anode X-ray tube comprising a dynamic pressure type sliding bearing, a having a filled liquid metal lubricant in the helical groove,
There is an end opening which is an annular gap communicating with the vacuum space at a position where the surface of the fixed body and the surface of the terminal portion of the rotating body are opposed to each other.
The hydrodynamic slide bearing includes a pair of thrust bearings that generate pressure in a direction along the central axis and three radial bearings that generate pressure in a direction perpendicular to the central axis.
These three radial bearings include first and second radial bearings and auxiliary third radial bearings that substantially support the rotating body in a direction perpendicular to the central axis. And
The third radial bearing has two sets of spiral grooves with opposite directions,
These helical grooves include a first bearing groove that generates pressure to push the liquid metal lubricant in a direction toward the first or second radial bearing when the rotating body rotates in a normal rotation direction. And a second bearing groove that generates pressure to push the liquid metal lubricant in the direction toward the end opening,
The first bearing groove occupies a larger area than the second bearing groove;
When the rotating body is rotating, in a normal case, a liquid metal lubricant is supplemented in a supplementary region composed of the second bearing groove and a part of the first bearing groove,
When the liquid metal lubricant is pushed into a wide portion of the first bearing groove, the pressure generated in the first bearing groove exceeds the pressure generated in the second bearing groove;
Rotation characterized in that the liquid metal lubricant returns to its original state captured in the supplementary region when the pressure to push the liquid metal lubricant into the third radial bearing decreases. Anode X-ray tube. A vacuum vessel that defines a vacuum space, and a fixed body that is mechanically supported by a part of the vacuum vessel and protrudes into the vacuum vessel or penetrates the vacuum vessel and has a central axis When the rotating body X-ray target is attached coaxially to and partially includes a coaxially mated substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body, the fixed body and the a spiral groove provided in the fitting portion between the rotary member, the rotary anode X-ray tube comprising a dynamic pressure type sliding bearing, a having a filled liquid metal lubricant in the helical groove,
There is an end opening which is an annular gap communicating with the vacuum space at a position where the surface of the fixed body and the surface of the terminal portion of the rotating body are opposed to each other.
The hydrodynamic slide bearing includes three thrust bearings that generate pressure in a direction along the central axis and two radial bearings that generate pressure in a direction perpendicular to the central axis.
These three thrust bearings include the first and second two thrust bearings and the auxiliary third thrust bearing which substantially support the rotating body in a direction parallel to the central axis. And
The third thrust bearing is provided with two sets of spiral grooves with opposite directions,
These spiral grooves include a first bearing groove that generates pressure to push the liquid metal lubricant in a large diameter direction when the rotating body rotates in a normal rotation direction, and a liquid metal lubricant in a small diameter direction. And a second bearing groove that generates pressure to push
A radius that becomes a boundary between the first bearing groove and the second bearing groove is a value larger than an average value of the maximum diameter and the minimum diameter of the third thrust bearing,
When the rotating body is rotating, in a normal case, the liquid metal lubricant is supplemented only in a supplemental region consisting of a large diameter portion in the bearing gap of the third thrust bearing,
When the liquid metal lubricant is pushed into a wide portion of the first bearing groove, the pressure generated in the first bearing groove exceeds the pressure generated in the second bearing groove;
Rotation characterized in that the liquid metal lubricant returns to its original state captured by the supplementary region when the pressure to push the liquid metal lubricant into the third thrust bearing decreases. Anode X-ray tube. The third radial bearing or the third thrust bearing is disposed at a position closest to the end opening in the sliding bearing,
When more liquid metal lubricant is pushed into the third radial bearing or into the third thrust bearing, it is pushed into a wider area in the first bearing groove and balanced,
3. The apparatus according to claim 1, wherein when the pressure to be pushed in is reduced, the pushed liquid metal lubricant is returned to the supplemental region to be balanced. 4. Rotating anode X-ray tube . The third radial bearing or the third thrust bearing is disposed at a position closest to the end opening in the sliding bearing,
When the rotating body is stationary, the liquid metal lubricant is present only in a part of the third radial bearing or a part of the third thrust bearing, and the liquid metal lubricant is present in a part other than these bearings. Usually separated from and collected from
When the gas pressure inside the fitting portion increases, the separated liquid metal lubricant is pushed in the direction of the end opening, and at this time, a part of the ring of the separated liquid metal lubricant is cut. Thus, a gas passage connecting the inside of the fitting portion and the vacuum space is temporarily generated and gas is discharged to the outside. The gas metal is discharged from the third radial bearing or the separated liquid metal lubricant. The space portion occupies a large proportion in the third radial bearing or in the third thrust bearing to the extent that it is performed before being pushed out from the third thrust bearing. Item 4. The rotating anode X-ray tube according to any one of items 3 to 4 . The third radial bearing or the third thrust bearing is disposed at a position closest to the end opening in the sliding bearing,
When the rotating body is stationary, the liquid metal lubricant is present only in a part of the third radial bearing or a part of the third thrust bearing, and the liquid metal lubricant is present in a part other than these bearings. Usually separated from and collected from
When the gas pressure inside the fitting portion increases, the separated liquid metal lubricant is pushed in the direction of the end opening, and at this time, a part of the ring of the liquid metal lubricant is cut and the fitting is performed. A gas passage connecting the inside of the part and the vacuum space is temporarily generated, and the gas is discharged to the outside. The gas is discharged from the separated liquid metal lubricant by the third radial bearing or the third thrust. The rotary anode type X according to any one of claims 1 to 4, wherein the amount of the separated liquid metal lubricant is reduced to the extent that it is performed before being pushed out of the bearing. Wire tube . The third adjacent to the radial bearing or the third thrust bearing, and the center and the one auxiliary bearing, and any of the hydrodynamic sliding bearing which substantially supported the rotating body by In the position sandwiched in the direction along the axis,
An annular forbidden band including an annular surface portion that is not wetted by the liquid metal lubricant is formed on the surface portion of the fixed body and the surface portion of the rotating body facing the surface of the fixed body with a minute gap therebetween. And
In the third radial bearing or in a part of the third thrust bearing, a liquid metal lubricant is always accumulated, and the liquid metal lubricant is in the form of a ring with the liquid metal lubricant in a portion other than these bearings. The rotary anode type X-ray tube according to any one of claims 1 to 5, wherein the rotary anode type X-ray tube is normally separated by a forbidden band. The portion of the fixed body in the rotating body substantially any said annular forbidden band and the thus sandwiched in a direction along the central axis position of the dynamic pressure type sliding bearing for rotatably supporting, said annular bandgap An opening having an opening width larger than the gap between the opposing surfaces and an annular deep groove having a depth larger than the opening width of the opening are provided adjacent to the annular forbidden band. It is and,
In the annular deep groove there is a liquid metal lubricant and a space portion,
The liquid metal lubricant in the annular deep groove is normally separated from the liquid metal lubricant in the third radial bearing or in the third thrust bearing by the annular forbidden band, and 7. The rotary anode X-ray tube according to claim 6 , wherein the rotary anode X-ray tube is configured to communicate with any one of the other hydrodynamic slide bearings that substantially support the rotating body . In said third surface portion of said rotating body spiral grooves are opposed to each other with a gap in a surface portion this surface portion of the fixed body in the region provided for a radial bearing or the third thrust bearing The volume of the first gap portion formed by being sandwiched between the surface portion of the fixed body that constitutes the annular forbidden band and the surface portion of the rotating body that is opposed to each other with a gap therebetween is second. of which the size Kuna' than the volume of the gap portion,
Even when all of the liquid metal lubricant filled in the second gap portion has moved into the third radial bearing or the third thrust bearing, the liquid metal lubricant does not support these auxiliary lubricants. The rotary anode type X-ray tube according to claim 6 or 7 , wherein the rotary anode type X-ray tube is adapted to stay in a bearing . The area of the surface portion of the fixed body or the rotating body in the region where the spiral groove for the third radial bearing or the third thrust bearing is provided is the surface portion of the fixed body constituting the annular forbidden band of which the size Kuna' than the area,
Even when all of the liquid metal lubricant filled in the gap portion of the annular forbidden band moves into the third radial bearing or the third thrust bearing, the liquid metal lubricant is used as an auxiliary material for these. The rotary anode type X-ray tube according to any one of claims 6 to 8 , wherein the rotary anode type X-ray tube is configured to stay in a simple bearing . The liquid metal lubricant in the third radial bearing or in the third thrust bearing is usually separated from the liquid metal lubricant in parts other than these bearings,
When the rotating body is stationary, a spiral groove of the third radial bearing or the third thrust bearing is provided even if the separated liquid metal lubricant is moved by the expansion of the internal gas. The rotation according to any one of claims 1 to 9, wherein the gas passage is formed by itself before being pushed out from the formed region, and the gas is exhausted. Anode X-ray tube.
By utilizing the centrifugal force in said annular deep groove liquid metal lubricant having moved to a position closer to the end opening than the third radial bearing via said annular forbidden band and the third radial bearing The rotary anode type X-ray tube according to any one of claims 6 to 10, further comprising feedback means for returning. The diameter of the outer surface portion of the fixed body and the inner surface portion of the rotating body opposed to the third radial bearing at a position closer to the end opening than the third radial bearing with a small gap therebetween is the third radial bearing. There is a small diameter part that is smaller than the diameter of the surface part of the bearing,
The feedback means includes a feedback hole that opens to the inner surface portion of the small-diameter portion of the rotating body and the vicinity of the bearing gap of the third radial bearing, and through which the liquid metal lubricant can pass .
The return hole is configured to return the liquid metal lubricant from the small-diameter portion into the annular deep groove via the third radial bearing and the annular forbidden band. 11. A rotating anode type X-ray tube described in item 11 . The rotating body has a first rotating body member to which the X-ray target is attached, and one end coupled to the first rotating body member , and is folded back in the axial direction while maintaining a gap in the first rotating body member. The second rotating body member attached coaxially and one end of the second rotating body member are coupled, and the second rotating body member is coaxially attached by folding back in the axial direction while maintaining a gap. A third rotating member that constitutes the hydrodynamic slide bearing,
The first rotary member and the second rotary member form a serial thermal path from the X-ray target to the third rotary member ,
Wherein the outer surface of the first of the inner surface of the rotating member the second rotary member, and each portion is an outer surface of said second of said inner surface of the rotary member third rotating member Are joined together to form a substantially closed space,
The charging device according to any one of claims 1 to 3, wherein charging means for charging the liquid metal lubricant that has come out of the end opening into the substantially closed space is provided in the second rotating member. 13. A rotating anode type X-ray tube described in any one of items 12 above . A vacuum vessel that defines a vacuum space, and a fixed body that is mechanically supported by a part of the vacuum vessel and protrudes into the vacuum vessel or penetrates the vacuum vessel and has a central axis When the rotating body X-ray target is attached coaxially to and partially includes a coaxially mated substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body, the fixed body and the a spiral groove provided in the fitting portion between the rotary member, the rotary anode X-ray tube comprising a dynamic pressure type sliding bearing, a having a filled liquid metal lubricant in the helical groove,
There is an end opening which is an annular gap communicating with the vacuum space at a position where the surface of the fixed body and the surface of the terminal portion of the rotating body are opposed to each other.
The rotating body has a first rotating body member to which the X-ray target is attached, and one end coupled to the first rotating body member , and is folded back in the axial direction while maintaining a gap in the first rotating body member. The second rotating body member attached coaxially and one end of the second rotating body member are coupled, and the second rotating body member is coaxially attached by folding back in the axial direction while maintaining a gap. A third rotating member that constitutes the hydrodynamic slide bearing,
The first rotary member and the second rotary member form a serial thermal path from the X-ray target to the third rotary member,
Wherein the outer surface of the first of the inner surface of the rotating member the second rotary member, and each portion is an outer surface of said second of said inner surface of the rotary member third rotating member Are joined together to form a substantially closed space,
A rotary anode X-ray tube characterized in that the second rotating body member is provided with a charging means for charging the liquid metal lubricant coming out from the end opening into the substantially closed space. . Guide means for guiding the liquid metal lubricant that has come out from the end opening toward the vacuum space to the vicinity of the charging means provided in the second rotating member is at least one of the fixed body and the rotating body. On one side ,
The guide means has an annular cover tip that is inserted into the gap between the second rotating member and the third rotating member and extends in the direction of the X-ray target;
The rotary anode X-ray tube according to any one of claims 13 and 14, wherein the tip of the annular cover is located in the vicinity of the charging means . The closing means provided in the second rotor member, have a non-wetting surface with a liquid metal lubricant passage of the liquid metal lubricant is usually blocked by the action of surface tension, centrifugal force Ri consists one-way passage passing is allowed only liquid metal lubricant when working,
The said one-way passage is provided in the middle of the thermal path | route from the said X-ray target to the said 3rd rotary body member in which the said slide bearing was provided , The any one of Claim 13 thru | or 15 characterized by the above-mentioned. The rotating anode type X-ray tube described in item 1 . The joined surface forming the substantially closed space is located in the middle of a thermal path from the X-ray target to the third rotating member provided with the slide bearing, and the third surface A portion that is higher than the temperature of the rotating member of
Even when the liquid metal lubricant in the slide bearing is in a liquid state, the temperature is high enough for the liquid metal lubricant in the substantially closed space to substantially react and solidify with the material on the surface. The rotating anode type X-ray tube according to claim 13, further comprising:   18. The rotary anode X-ray tube according to claim 1, a storage container for storing the rotary anode X-ray tube, and the rotary anode X-ray tube fixed to the storage container. A holding mechanism, a stator for applying rotational torque to the rotating body in the rotary anode X-ray tube from outside the vacuum vessel of the rotary anode X-ray tube, and electrons being emitted in the rotary anode X-ray tube A rotary anode type X-ray tube device comprising a high voltage terminal for supplying a negative high voltage to the cathode. A vacuum vessel that defines a vacuum space, and a fixed body that is mechanically supported by a part of the vacuum vessel and protrudes into the vacuum vessel or penetrates the vacuum vessel and has a central axis When the rotating body X-ray target is attached coaxially to and partially includes a coaxially mated substantially cylindrical portion while maintaining a small bearing clearance on the outer circumference of the fixed body, the fixed body and the a spiral groove provided in the fitting portion of the rotating body, and the dynamic pressure type slide bearing having a liquid metal lubricant filled in the helical groove, in the manufacturing method of the rotating anode X-ray tube having a,
A first rotary member, wherein the X-ray target is attached, and a second rotor member mounted coaxially folded axially with a gap to the first rotary member, the second by then combining the third rotating member constituting the hydrodynamic slide bearing is mounted coaxially assembling the rotating body folded axially with a gap to the rotating member of the first together with the outer surface of the inner surface of one of the rotating member a second rotary member, and an outer surface of said inner surface of the second rotor member third rotating member at a portion, respectively Combining to form a substantially closed space and forming a serial thermal path from the X-ray target to the third rotor member ;
Providing three radial bearing spiral grooves on the surface of the fixed body, and forming two sets of spiral grooves having different areas in one of the spiral grooves;
And a step of providing the second rotating member with charging means for charging the liquid metal lubricant that has come out from the terminal portion of the rotating member into the substantially closed space. X-ray tube manufacturing method.

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